Redirect is recognized from Google/Seobility as duplicate content

[tisto]

https://plone.de/services/dienstleister redirects to https://plone.de/services/plone-agentur. However, the Google Search Console detects it as duplicated content:

https://search.google.com/search-console/index/drilldown?resource_id=https%3A%2F%2Fplone.de%2F&item_key=CAMYDyAC

Seobility as well:

https://www.seobility.net/en/venture/analysis/?listtype=titledupe&id=756641

Curl shows that the redirect URL returns a 200 response:

curl --head https://plone.de/services/dienstleister
HTTP/2 200
date: Mon, 13 May 2024 02:58:36 GMT
content-type: text/html; charset=utf-8
vary: Accept-Encoding
cf-cache-status: DYNAMIC
report-to: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v4?s=%2BFNB2Oab8wx6Mo%2BiN2wOEfshIAlsiQwQBb%2FwzsIj%2BlhY3%2BDrPx5DeM6O9OI67kCdG0gW5iNwCCJyAA%2FAlxiC26%2BH8rWJlJzsR2p7nHmUpVXLNuhA3%2FjoqjMoH%2B1ZGr58Z%2Fwv4vwBdw%3D%3D"}],"group":"cf-nel","max_age":604800}
nel: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
server: cloudflare
cf-ray: 882f63426aad9b70-FRA
alt-svc: h3=":443"; ma=86400

Relevant tickets in Core:

plone/volto#4800
plone/plone.rest#135 (comment)