Nextcloud and Onlyoffice can be access in HTTPS Both services can ping each others using the addresses states on the

NC config page

When I save I got:

Error when trying to connect (Error occurred in the document service: Error while downloading the document file to be converted.) (version 8.3.0.94)

Logs on Onlyoffice:

nextcloud-onlyoffice | [2025-03-29T18:31:24.788] [ERROR] [localhost] [check_490634411] [userId] nodeJS - error downloadFile:url=http://nextcloud-app/index.php/apps/onlyoffice/empty?doc=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJhY3Rpb24iOiJlbXB0eSJ9.HO8yVThljmrKFAiXsGoWMtnWnjfNFj-idymye3GiplM%3Battempt%3D3%3Bcode%3Anull%3Bconnect%3Anull Error: Error response: statusCode:400; headers:{"date":"Sat, 29 Mar 2025 18:31:24 GMT","server":"Apache/2.4.62 (Debian)","referrer-policy":"no-referrer","x-content-type-options":"nosniff","x-frame-options":"SAMEORIGIN","x-permitted-cross-domain-policies":"none","x-robots-tag":"noindex, nofollow","x-xss-protection":"1; mode=block","x-powered-by":"PHP/8.2.27","set-cookie":["oc15g94igmmg=fa5786d618da63752dc936e885dcf8e0; path=/; secure; HttpOnly; SameSite=Lax","oc_sessionPassphrase=UH3UchW4C3Kc%2BpmtSZ5fh1xXq9eQTQ8xJtphvQ4Tm%2BAUNBfWJ7Fr2VByyEdVviUtJGGwptZDFlTHPSGecyXtU4WoH5fs3Xd7DI8%2BHePakMBb5osZoGvq%2F28KuyBUbAM2; path=/; secure; HttpOnly; SameSite=Lax","oc15g94igmmg=fa5786d618da63752dc936e885dcf8e0; path=/; secure; HttpOnly; SameSite=Lax","__Host-nc_sameSiteCookielax=true; path=/; httponly;secure; expires=Fri, 31-Dec-2100 23:59:59 GMT; SameSite=lax","__Host-nc_sameSiteCookiestrict=true; path=/; httponly;secure; expires=Fri, 31-Dec-2100 23:59:59 GMT; SameSite=strict","oc15g94igmmg=fa5786d618da63752dc936e885dcf8e0; path=/; secure; HttpOnly; SameSite=Lax"],"content-security-policy":"default-src 'self'; script-src 'self' 'nonce-EyL8f5e9IBlNqN+Z1SQPFRiKGGBzHLsSax9P/7eMgm0='; style-src 'self' 'unsafe-inline'; frame-src *; img-src * data: blob:; font-src 'self' data:; media-src *; connect-src *; object-src 'none'; base-uri 'self';","connection":"close","transfer-encoding":"chunked","content-type":"text/html; charset=UTF-8"};
nextcloud-onlyoffice | at Request.fResponse (/snapshot/server/Common/sources/utils.js)
nextcloud-onlyoffice | at Request.emit (node:events:527:28)
nextcloud-onlyoffice | at Request.onRequestResponse (/snapshot/server/Common/node_modules/request/request.js:1066:10)
nextcloud-onlyoffice | at ClientRequest.emit (node:events:527:28)
nextcloud-onlyoffice | at HTTPParser.parserOnIncomingClient [as onIncoming] (node:_http_client:631:27)
nextcloud-onlyoffice | at HTTPParser.parserOnHeadersComplete (node:_http_common:128:17)
nextcloud-onlyoffice | at Socket.socketOnData (node:_http_client:494:22)
nextcloud-onlyoffice | at Socket.emit (node:events:527:28)
nextcloud-onlyoffice | at addChunk (node:internal/streams/readable:315:12)
nextcloud-onlyoffice | at readableAddChunk (node:internal/streams/readable:289:9)
nextcloud-onlyoffice | at Socket.Readable.push (node:internal/streams/readable:228:10)
nextcloud-onlyoffice | at TCP.onStreamRead (node:internal/stream_base_commons:190:23)

This is the app config:

This is the Onlyoffice backend config:

Any idea?