i use opera for 20 years . 3 years ago, i sync my desktop1 whit my phone2. It worked fine till i noticed the sync was off and an error 404 occurred https://auth.opera.com/account/v2/desktop/login

Now I tried to sync another device3 but the error still appears on the first device. Although the second one and the third one are working fine between them on the same account .The second device stopped sync with desktop1 since the error appears last year and now sync with third, without new bookmarks saved on desktop1.
So even being logged in already, if i try to enable Sync, i get this message, yes.
Version:85.0.4341.22