Account removed automatically when it shouldn't: "Credentials for this account were no longer valid"

[mahibi]

Reported via mail:

Samsung Galaxy S24 Ultra smartphone. Synology DS923+ server, Nextcloud Hub 26 Spring (34.0.3) container.

The Nextcloud Talk (beta) program asks to re‑enter the server address and login/password several times a day.

It was also noticed that the app launches in multiple instances.

[mahibi]

might be related to #6529