Thanks a lot for the help and the links @289wk and @Saoiray (again), they really pointed me in the right direction. It turns out the issue comes from Brave (Chromium) relying on different keyring backends depending on the desktop environment ,libsecret for GNOME and KWallet for KDE. If you switch DEs or don’t unlock the expected keyring, Brave can’t access stored passwords or sessions properly. To fix this, I decided to stick with GNOME Keyring even on KDE. First, I opened KWalletManager and disabled the “Use KWallet for storing secret service data” option under its settings. Then I created a .desktop file at ~/.config/autostart/gnome-keyring-daemon.desktop to autostart GNOME Keyring in KDE. In that file, I set the command to gnome-keyring-daemon --foreground --components=pkcs11,secrets --control-directory=/run/user/1000/keyring/. I also edited the Brave launcher (or .desktop entry) to include --password-store=gnome-libsecret(optional , just in case). Now Brave consistently uses GNOME Keyring across both GNOME and KDE without losing login sessions or throwing password storage errors. Hopefully this helps others who hit the same problem when switching between desktop environments.