After logging in on mobile web (on hu.m.wikipedia.org, with Chrome 83 on Android 10 on a Pixel 4) I get the error shown on the first screenshot below (the message key is centralauth-error-badtoken). The login works otherwise, I'm logged in even on the screen with the error.
When visiting en.m.wiktionary.org, I see that edge login has failed; I'm not immediately logged in, but get logged in in a second or so.
When visiting m.mediawiki.org, both edge login and autologin fail; I'm not logged in at all.
|login error||edge login failure||autologin failure|
Logging in on m.mediawiki.org works without an error message, and logs me in to some projects (commons.wikimedia.org, at least) but on most projects including Wikipedias I remain logged out (no autologin, either).
I have seen the error in the past, so this is not (or at a minimum, not fully) related to SameSite changes or to T257853: CentralAuth edge login broken on desktop (coinciding with SameSite rollout).