When I switched to mango a few months ago (I'll have to make a blog article about that some day, so you know why, but mostly it's the monocle layout, awesome for apps that don't like tiling), I also started using Noctalia, which adds "DE-like" functionalities to a window manager.

But then, I also later switched from sddm to noctalia-greeter, so I could have a greeter matching my mangowm session theme. I also wanted Noctalia to be able to sync the greetd theme without needing to authenticate each time.

So I had to make changes : greetd running as the greet user, that was allowing noctalia. That allowed noctalia to sync the theme just fine automatically without issue for a while... until an update for that greeter changed something, and my gnome-keyring keyring wasn't unlocked at login (which meant entering my password a second time), as the noctalia-greeter wasn't running as the "usual" user (probably root ?)

So, here's the link to the portion of the gnome-keyring archlinux wiki page with the options you need to add (the ones with "gnome_keyring") so that logging in also tries to unlock the gnome-keyring with the same password you used at login :

https://wiki.archlinux.org/title/GNOME/Keyring#PAM_step

That solved my issue, my keyring is unlocked when logging in automatically again !