Vikunja.cloud keeps logging me off regardless of "Remember me" being checked

I just tested the unstable Desktop app from post desktop-app-and-web-app-aggressively-logs-out/4081

Nothing changes. After 10 mins app logs me out, no matter if I click “Remember me” or not.

I checked also 2 different Wifi networks from 2 different providers - no change.
This is ridiculous. I’ve payed 40 euros for Vikunja Cloud that I can barely use.