User language settings not saved on server updates

[GeorgelT]

Hello,

I've been struggling with this for the better part of half a year, looked at previous issues and it does not seem to be addressed. It happened again today making me lose 1h because of it so I decided to make an issue.

Context: Users that use other than server default/OS language on their seahub page and set it in settings. Everything in seahub is now in the correct language, including Office integrations and their date/locale formats.

Problem: On server update, or user session expiration requesting relogin(not sure which one it is, but usually after admins do server maintenance), set language is no longer set. Interface is now again in default/OS language. This leads to any Office integrations to also be in "new"/default locale, screwing up any dates and dictionaries that might have worked previously. For example we have a spreadsheet with dates, and it gets screwed up every time this happens because ISO is not US Date format. The file thjen is locked for half an hour to 1 hour even after language is changed again.

Desired behaviour: User language settings should be saved between sessions/server upgrades.