Chromium based browsers want to use gnome-keyring.
My MX Linux (which installs with xfce) seems to install that too (at least there is a "password optional pam_gnome_keyring.so " in /etc/pam.d/common-password, and there was something in etc/pam.d/lightdm too).
gnome-keyring does not get unlocked when I log into TDE/TDM, so these browsers ask for a password to unlock the keyring.
My solution so far has been to use plaintext paswords (--password-store=basic) and I can live with it, because these are simply passwords to access websites, but it raises a question: is there a way to unlock gnome-keyring or KDE-wallet when loging into TDE (or to have chromium ude TDE's wallet)?