Editing Files from SMB/CIFS not possible

Hi Guys,
hope you are all doing well.
I have a debian VM installed with Nextcloud latest version (26.0.1) and a dedicated debian VM with the latest documentserver of onlyoffice (7.3.3.49). Als the integration app on the nextcloud server is installed in it’s latest version (7.8.0).

It works fine when editing or creating a new file directly on the nextcloud server, but it shows a “Download failed” message, when doing that on an SMB/CIFS share. I know this combination made problems back several years ago, but I think it should work now. The only known issue I found in this combination is with the co-authoring feature, but I currently don’t need that.

The nextcloud and onlyoffice server are located in the same vLAN, the SMB/CIFS storage is located in a different one and routed over a firewall. On that firewall, the SMB port is allowed, so nextcloud can access it without problems. Between the nextcloud and onlyoffice server is no firewall.

Nextcloud uses an official letsencrypt cert and onlyoffice uses a self-signed one, but the root- and intermediate-ca certs are copied to the nextcloud server. So the connection between these two work with cert verification.

The only error I found was in the converter-log on the onlyoffice server:

[2023-05-23T13:10:47.840] [ERROR] [localhost] [26535865] [xxx] nodeJS - error downloadFile:url=https://hub.domain.tld/index.php/apps/onlyoffice/download?doc=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJhY3Rpb24iOiJkb3dubG9hZCIsImZpbGVJZCI6ODcyODUsInVzZXJJZCI6ImJlbmphbWluLmtvZW5pZyJ9.FkpscCe2fFCWuYeFTiLP8fc5IPNqkvt9q4VqnZ5b2hs;attempt=3;code:undefined;connect:undefined Error: Error response: statusCode:404; headers:{"date":"Tue, 23 May 2023 11:10:47 GMT","server":"Apache","strict-transport-security":"max-age=15552000","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","expires":"Thu, 19 Nov 1981 08:52:00 GMT","cache-control":"no-cache, no-store, must-revalidate","pragma":"no-cache","content-security-policy":"default-src 'none';base-uri 'none';manifest-src 'self';frame-ancestors 'none'","x-request-id":"PG74N3cZGHne7aXFRhb9","content-disposition":"attachment; filename=\"New spreadsheet.xlsx\"","feature-policy":"autoplay 'none';camera 'none';fullscreen 'none';geolocation 'none';microphone 'none';payment 'none'","set-cookie":["oc0micu9xkf5=9l7l9dglhv027tg606r7dqabfg; path=/; secure; HttpOnly; SameSite=Lax;HttpOnly;Secure;SameSite=Strict","oc_sessionPassphrase=DUlFZ41v9xRWZw%2Fv7RHjP%2BzF8DOaoRsmzgrIuHNs3PDzAzk%2FWUFIv3SKxgRXMKABh%2FEsohgkiCUyIp2zeZZKsesHr%2FH%2BbSQPZ1j9zvkkPRrBd7hFNlusV16%2FTHYE3veI; path=/; secure; HttpOnly; SameSite=Lax;HttpOnly;Secure;SameSite=Strict","oc0micu9xkf5=er1t3pdvd308qmqihrhnp81h9p; path=/; secure; HttpOnly; SameSite=Lax;HttpOnly;Secure;SameSite=Strict","oc0micu9xkf5=er1t3pdvd308qmqihrhnp81h9p; path=/; secure; HttpOnly; SameSite=Lax;HttpOnly;Secure;SameSite=Strict","__Host-nc_sameSiteCookielax=true; path=/; httponly;secure; expires=Fri, 31-Dec-2100 23:59:59 GMT; SameSite=lax;HttpOnly;Secure;SameSite=Strict","__Host-nc_sameSiteCookiestrict=true; path=/; httponly;secure; expires=Fri, 31-Dec-2100 23:59:59 GMT; SameSite=strict;HttpOnly;Secure;SameSite=Strict","oc0micu9xkf5=er1t3pdvd308qmqihrhnp81h9p; path=/; secure; HttpOnly; SameSite=Lax;HttpOnly;Secure;SameSite=Strict","oc0micu9xkf5=er1t3pdvd308qmqihrhnp81h9p; path=/; secure; HttpOnly; SameSite=Lax;HttpOnly;Secure;SameSite=Strict"],"content-length":"0","keep-alive":"timeout=5, max=100","connection":"Keep-Alive","content-type":"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"};
    at Request.fResponse (/snapshot/server/build/server/Common/sources/utils.js)
    at Request.emit (events.js:400:28)
    at Request.onRequestResponse (/snapshot/server/build/server/Common/node_modules/request/request.js:1059:10)
    at ClientRequest.emit (events.js:400:28)
    at HTTPParser.parserOnIncomingClient (_http_client.js:647:27)
    at HTTPParser.parserOnHeadersComplete (_http_common.js:127:17)
    at TLSSocket.socketOnData (_http_client.js:515:22)
    at TLSSocket.emit (events.js:400:28)
    at addChunk (internal/streams/readable.js:293:12)
    at readableAddChunk (internal/streams/readable.js:267:9)
    at TLSSocket.Readable.push (internal/streams/readable.js:206:10)
    at TLSWrap.onStreamRead (internal/stream_base_commons.js:188:23)

Any suggestions what the problem could be? I don’t know if that problem started to happen after the last update of nextcloud and onlyoffice or if it hasn’t worked since the beginning. Normaly I edit the files from the offline copy on the notebook.

Thanks a lot and best regards