[Bug]: Timeouts due to large number of synchronous requests by OnlyOffice

⚠️ This issue respects the following points: ⚠️ • This is a bug, not a question or a configuration/webserver/proxy issue. • This issue is not already reported on [Github]( OR [Nextcloud Community Forum]( _(I've searched it)_. • Nextcloud Server is up to date. See [Maintenance and Release Schedule]( for supported versions. • I agree to follow Nextcloud's [Code of Conduct]( Bug description Nextcloud server ending up in timeouts (Error 504 Gateway Time-out) when OnlyOffice is requesting thumbnails. Already contacted OnlyOffice support who came to the following conclusion: > While working on the bug, we came to the conclusion that the solution needs to be deployed on the Nextcloud side and here is why: > > The mechanism for converting thumbnails is implemented on the Nextcloud side and ONLYOFFICE works here as a tool by converting the thumbnail of the defined size from the exact file. Conversion requests are synchronised, Nextcloud triggers …