Hi,
It looks like the main issue here is the cookie settings in Opera. Since you’ve blocked third-party cookies, Spotify might not be able to keep you signed in between sessions. Disabling this setting or adding Spotify as an exception could help fix the login issue.
Your use of secure DNS and tracker blocking is good for privacy, but sometimes these settings can interfere with how websites store login details. Try turning them off one by one to see if Spotify stays logged in when you restart Opera.
Another simple fix is clearing your browser cache and cookies, then logging in again. After that, allow cookies for Spotify specifically so it remembers your session.
If none of these steps help, and since you mentioned the issue is still happening, you can check the discussion here for more details: https://community.spotify.com/t5/Accounts/I-got-randomly-logged-out-of-my-spotify premium-account-and-it-says-it/td-p/6399398
If none of this works, you might also consider updating Opera or even trying Spotify’s desktop app instead of the browser. It usually handles login sessions more reliably.
Regards