Annoying, every time Nextcloud wants to log in or authenticate itself via the browser.
After I installed Linux Mint Nextcloud, everything worked fine. However, it was a bit annoying that I had to re-authenticate to Nextcloud via the browser after every restart.
The reason was that no wallet was installed. After installing and setting up the KDE wallet, the authentication was retained and Nextcloud was able to connect automatically after the wallet was activated.
In my case, a password is now also required. However, this unlocks the entire wallet. Alternatively, the password can also be deactivated via the “kwalletmanager”. The application must be installed separately.