Every loop out payment fails with FAILURE_REASON_INCORRECT_PAYMENT_DETAILS

[asheswook]

Expected behavior

success loop out

Actual behavior

Every tries fails.
A 30000 sats prepayment didn't successfully settle and keeps failing with FAILURE_REASON_INCORRECT_PAYMENT_DETAILS.

{
    "amt": "5000000",
    "id": "2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9",
    "id_bytes": "2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9",
    "type": "LOOP_OUT",
    "state": "FAILED",
    "failure_reason": "FAILURE_REASON_OFFCHAIN",
    "initiation_time": "1766537421320716462",
    "last_update_time": "1766539550382248533",
    "htlc_address": "bc1pja9qgz70e9vajx0ydjvyxeufj2wlvgszvjmffwxaleurrgsmn79stgd9y3",
    "htlc_address_p2wsh": "",
    "htlc_address_p2tr": "bc1pja9qgz70e9vajx0ydjvyxeufj2wlvgszvjmffwxaleurrgsmn79stgd9y3",
    "cost_server": "0",
    "cost_onchain": "0",
    "cost_offchain": "0",
    "last_hop": "",
    "outgoing_chan_set": [],
    "label": "",
    "asset_info": null
},

I talked to @alexbosworth on Slack channel and I'm attaching contents below.

So, What's the problem?

• Find a route fails?

My node is directly connected to LOOP (20M).
Result same if attempting through another node connected to the LOOP channel.

Below is an attempt to find a route to the invoice I checked in the loop log

lncli estimateroutefee --pay_req lnbc300u1p55chynpp58xhzwcspf4rpraymg52744wsufg5cgu25z0nslq5xlhu8kg3ffgqdq2wpex2urp0ycqzxgxq97zvuqrzjqgwf02g2gy0l9vgdc25wxt0z72wjlfyagxlmk54ag9hyvrdsw37smapyqqqqqqqq2qqqqqqqqqqqqqqq9qsp5m29new4melyf3a6lw375cz0r6rdq2hg9u4ef8grlpczcd6yc873s9qxpqysgqmh2s0ktcm7zcrd4q59pk6vv2efa07yj7cd8tlvzt2mp530mam7wpcf449kmj7j8jfsxa8l8lw5jwa6w0elsp7dklmtyqhcuccmw7r8gprx6zrs
{
    "routing_fee_msat":  "0",
    "time_lock_delay":  "929575",
    "failure_reason":  "FAILURE_REASON_NONE"
}

lncli estimateroutefee --pay_req lnbc4705430n1p55chynpp54vdalanrgyxjw0hllcuklyxuqu2r65gwx9lx93yydyeu5s779jqsdy9wdmkzupq95s8xcmjd9c8gw3qx5cnyvpnx9nrjd3hxd3rgvf4xsmkywpj8yukxce3xajrsvmzxsekvwp4xcukzcfnv93nqctr8ymrxvrxvymrsv3kvgmngd3nxf3rxdf4vcexxcqzxgxq97zvuqrzjqgwf02g2gy0l9vgdc25wxt0z72wjlfyagxlmk54ag9hyvrdsw37smapyqqqqqqqq2qqqqqqqqqqqqqqq9qsp58s8nc9njerusg9t78443r5wphzek8xpcpzx9nh7wylccqg26u4lq9qxpqysgqe348klvy5j9njwvx0fl7ct75jvsl668phv5p2k2jx4n6fxdujf5x50jsgn72eaym5hr4h8gsf9du59y6vzgjn0j7dz9xyhe9hjeg05spt0w5rv
{
    "routing_fee_msat":  "0",
    "time_lock_delay":  "929575",
    "failure_reason":  "FAILURE_REASON_NONE"
}

• Liquidity?

There's a LOOP channel with sufficient liquidity.

• Try with different amount?

Same result (500k try)

• Try with manually specify LOOP channel or, another channel connected to LOOP channel

Same result (I checked another node that connected to LOOP is sufficient liquidity to routing my loop out). (Additional Information that may help: not immediately fails, after about 30 minutes fails.)

To reproduce

Requests loop out with the default settings.

System information

• both GUI (Lightning Terminal) and Loop CLI with loopd
• Linux, no umbrel
• AWS t3 CPU (amd64)
• Amazon Linux 2023
• LND 0.19.1-beta (Also I tried after upgrade/downgrade LND 0.20.0 and 0.19.3 but same result) (postgres backed)

2025-12-24 00:50:20.398 [INF] LOOPD: Loop out request received
2025-12-24 00:50:20.465 [INF] LOOP: LoopOut 0.05000000 BTC to [DETACTED] (channels: )
2025-12-24 00:50:20.606 [INF] LOOP: Initiating swap request at height 929195: amt=0.05000000 BTC, expiry=929295
2025-12-24 00:50:20.740 [INF] L402: Payment of L402 token is required, paying invoice
2025-12-24 00:50:21.168 [INF] LNDC: Payment 68ba93e170329031d926011c9fae06d2e022e4476f6fb314f359ee94e8e078dc completed
2025-12-24 00:50:21.321 [INF] LOOP: 2449c1 Htlc address (P2TR): [DETACTED]
2025-12-24 00:50:21.324 [INF] LOOP: 2449c1 Server message: Use AutoLoop - it is really good, give it a try
2025-12-24 00:50:21.325 [INF] LOOP: 2449c1 Loop out swap state: Initiated
2025-12-24 00:50:21.325 [INF] LOOP: 2449c1 Sending swap payment lnbc49750430n1p55kwxdpp5y3yuz2gzevjvmxcu5a24rshpm7hhuk5463t
z05ytqcrcr97wfnusdy9wdmkzupq95s8xcmjd9c8gw3qx5cnyvpexu6xzvp5xp3xxenr8y6njepexyuk2dpkvvunsdpnxcmnswfexgukge3kxgerqv3kx33rvwf
5vguxgerxv5mnsve3vyerzc3evcuxycqzxgxq97zvuqrzjqgwf02g2gy0l9vgdc25wxt0z72wjlfyagxlmk54ag9hyvrdsw37smapyqqqqqqqq2qqqqqqqqqqqq
qqq9qsp5m3m7v7x9w25lwljd07eg6xqupkuj3eya8a3py9847k5dladx02sq9qxpqysgqzveghlxxks6w5cf6ymvwv9jq3x90pdhswjcy7emqr72zrxq8j8hzmy
qxg6j927908y5k2jlq6d5q3q97n6d6sjj30474ujnchuyctkgqpncsy5
2025-12-24 00:50:21.453 [INF] LOOP: 2449c1 Server update: SERVER_INITIATED received, timestamp: 2025-12-24 00:50:21.2565489
09 +0000 UTC
2025-12-24 00:50:21.454 [INF] LOOP: 2449c1 Server recommended routing plugin: Low/High
2025-12-24 00:50:21.455 [INF] LOOP: 2449c1 Sending prepayment lnbc300u1p55kwxdpp5pyqe4smp35dfvmhzx2qq7r68lnxw47u8mf3aaauesl
5awpry03wqdq2wpex2urp0ycqzxgxq97zvuqrzjqgwf02g2gy0l9vgdc25wxt0z72wjlfyagxlmk54ag9hyvrdsw37smapyqqqqqqqq2qqqqqqqqqqqqqqq9qsp
5kwym045gjs5nzxjunuuc4x8ek76znzcfn6rpchzkt5ujpczdk6tq9qxpqysgq9fjtw825u00hal00p4pcmprvagg3cmn0d3ssza5ynw43s3es6x7sn0shhmwv2
pqvt2xgr2vyzapzvdazul4z4ekuaxhfp3gsnrvp6kqpvhd8du
2025-12-24 00:50:21.455 [INF] LOOP: 2449c1 Register 1 conf ntfn for swap script on chain (hh=929195)
2025-12-24 00:50:21.455 [INF] LOOP: 2449c1 Checking if preimage reveal height 929275 was exceeded (current height is 929195
)
2025-12-24 00:50:21.455 [INF] LOOP: 2449c1 Waiting for either htlc on-chain confirmation or off-chain payment failure
2025-12-24 00:50:21.455 [INF] LOOP: 2449c1 Payment (09019ac3618d1a966ee232800f0f47fccceafb87da63def79987e9d704647c5c) try c
ount 1/1 (plugin=None)
2025-12-24 00:50:21.522 [INF] LOOP: 2449c1 Payment 09019ac3618d1a966ee232800f0f47fccceafb87da63def79987e9d704647c5c: state=
IN_FLIGHT, inflight_htlcs=0, inflight_amt=0 mSAT
2025-12-24 00:50:21.549 [INF] LOOP: 2449c1 Payment 09019ac3618d1a966ee232800f0f47fccceafb87da63def79987e9d704647c5c: state=
IN_FLIGHT, inflight_htlcs=1, inflight_amt=30000000 mSAT
2025-12-24 00:51:55.479 [INF] LOOP: Received block 929196
2025-12-24 00:51:55.479 [INF] LOOP: 2449c1 Checking if preimage reveal height 929275 was exceeded (current height is 929196
)
2025-12-24 00:52:10.808 [INF] LOOP: Received block 929197
2025-12-24 00:52:10.808 [INF] LOOP: 2449c1 Checking if preimage reveal height 929275 was exceeded (current height is 929197)
2025-12-24 01:02:04.440 [INF] LOOP: Received block 929198
2025-12-24 01:02:04.440 [INF] LOOP: 2449c1 Checking if preimage reveal height 929275 was exceeded (current height is 929198)
2025-12-24 01:12:56.545 [INF] LOOP: Received block 929199
2025-12-24 01:12:56.545 [INF] LOOP: 2449c1 Checking if preimage reveal height 929275 was exceeded (current height is 929199)
2025-12-24 01:15:34.567 [INF] LOOP: Received block 929200
2025-12-24 01:15:34.567 [INF] LOOP: 2449c1 Checking if preimage reveal height 929275 was exceeded (current height is 929200)
2025-12-24 01:17:21.784 [INF] LOOP: Received block 929201
2025-12-24 01:17:21.784 [INF] LOOP: 2449c1 Checking if preimage reveal height 929275 was exceeded (current height is 929201)
2025-12-24 01:23:41.320 [INF] LOOP: 2449c1 Server update: SERVER_FAILED_OFF_CHAIN_TIMEOUT received, timestamp: 2025-12-24 01:23:41.257356283 +0000 UTC
2025-12-24 01:23:41.320 [INF] LOOP: 2449c1 swap subscription: server finished serving updates
2025-12-24 01:23:41.588 [INF] LOOP: 2449c1 Payment 09019ac3618d1a966ee232800f0f47fccceafb87da63def79987e9d704647c5c: state=IN_FLIGHT, inflight_htlcs=1, inflight_amt=30000000 mSAT
2025-12-24 01:23:41.597 [INF] LOOP: 2449c1 Payment 09019ac3618d1a966ee232800f0f47fccceafb87da63def79987e9d704647c5c: state=FAILED
2025-12-24 01:23:41.597 [INF] LOOP: 2449c1 Failed prepayment: payment failed: FAILURE_REASON_INCORRECT_PAYMENT_DETAILS
2025-12-24 01:23:41.597 [INF] LOOP: 2449c1 Canceling swap: 1 payment failed: FAILURE_REASON_INCORRECT_PAYMENT_DETAILS, 1 attempts
2025-12-24 01:23:41.725 [WRN] LOOP: 2449c1 Could not report failure: rpc error: code = Unknown desc = cancel swap failed
2025-12-24 01:23:41.725 [INF] LOOP: 2449c1 Wait for server pulling off-chain payment(s)
2025-12-24 01:25:49.158 [INF] LOOP: 2449c1 Acquired routing plugin Low/High for payment 2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9
2025-12-24 01:25:49.158 [INF] LOOP: 2449c1 Payment (2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9) try count 1/3 (plugin=Low/High)
2025-12-24 01:25:49.218 [INF] LOOP: 2449c1 Payment 2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9: state=IN_FLIGHT, inflight_htlcs=0, inflight_amt=0 mSAT
2025-12-24 01:25:49.252 [INF] LOOP: 2449c1 Payment 2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9: state=IN_FLIGHT, inflight_htlcs=1, inflight_amt=4975043000 mSAT
2025-12-24 01:25:50.244 [INF] LOOP: 2449c1 Payment 2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9: state=IN_FLIGHT, inflight_htlcs=1, inflight_amt=4975043000 mSAT
2025-12-24 01:25:50.251 [INF] LOOP: 2449c1 Payment 2449c12902cb24cd9b1ca75551c2e1dfaf7e5a95d45627d08b06078197ce4cf9: state=FAILED
2025-12-24 01:25:50.382 [INF] LOOP: 2449c1 Swap payment failed: payment failed: FAILURE_REASON_INCORRECT_PAYMENT_DETAILS
2025-12-24 01:25:50.382 [INF] LOOP: 2449c1 Swap completed: FailOffchainPayments (final cost: server 0 BTC, onchain 0 BTC, offchain 0 BTC)
2025-12-24 01:25:50.387 [INF] LOOP: 2449c1 Loop out swap state: FailOffchainPayments

Dec 24 21:28:24 lnd[3604]: 2025-12-24 21:28:24.263 [WRN] CRTR: Attempt 45000 for payment 5ae3aea53b129b4f5ae1980f79b26d3b87b7532a9f42f740e50e3a095ecec723 failed: IncorrectOrUnknownPaymentDetails(amt=30000000 mSAT, height=929327)@2
Dec 24 21:28:24 lnd[3604]: 2025-12-24 21:28:24.277 [WRN] CHDB: Payment(5ae3aea53b129b4f5ae1980f79b26d3b87b7532a9f42f740e50e3a095ecec723): cannot register HTLC attempt: payment has already failed, current status: Failed
Dec 24 21:28:24 lnd[3604]: 2025-12-24 21:28:24.291 [ERR] CRTR: Payment 5ae3aea53b129b4f5ae1980f79b26d3b87b7532a9f42f740e50e3a095ecec723 failed: incorrect_payment_details