Blocking nextcloud update on o2switch from version 24 to 25 and attempt to restore

Sorry for my poor english.
Here is my problem. I wanted to update my version of nextcloud on o2switch with the updater, I was starting from a fairly old version and the update was done correctly from version to version until 24, the switch to the 25 seemed to go all the way until the launch, at which point a blank page appears and nothing. In FTP in the Nextclouddata/updaterxxx/backups folder I spotted nextcloud backups but I don’t know how to restore them. I launched the o2switch JetBackup tool and restored the Nextcloud and Nextclouddata folders and the corresponding database to an earlier version. Without success. I’m guessing there’s a setting somewhere. Reading me you have understood that I am only an amateur even if I have some notions, so thank you in advance for your kindness with if possible answers adapted to my level, but I have seen such on this forum I am confident.

If it’s a Nextcloud issue, there will be errors in your nextcloud.log file located in your NC datadirectory.

That is the place to look both for the issue you had after upgrading as well when you tried to use your backup version.