I've been wondering if there's been issues especially WRT Sequoia 15.3 breaking things.
I'm **not** On Nord (I use Mullvad), but ever since 15.3, I am once again (as I had when 15.0 was first released but fixed when 15.1 released) been having weird issues w/ Mullvad enabled (iCloud won't sync; can't access Gmail accounts through Apple Mail app, for instance).