not sure if your arch issue is related to that or not
read the whole post and see if it help or not
and for the --password-store arg from https://support.brave.com/hc/en-us/articles/360044860011-How-Do-I-Use-Command-Line-Flags-in-Brave
it say
Specifies which encryption storage backend to use. Possible values are kwallet, kwallet5, gnome, gnome-keyring, gnome-libsecret, basic. Any other value will lead to Chrome detecting the best backend automatically. TODO(crbug.com/571003): Once PasswordStore no longer uses the Keyring or KWallet for storing passwords, rename this flag to stop referencing passwords. Do not rename it sooner, though; developers and testers might rely on it keeping large amounts of testing passwords out of their Keyrings or KWallets.
not sure if basic will be the default encypt or unencrypted
so see if the seahorse help or not and have a nice day ![]()