@wildimpresario Hello and Welcome to the Vivaldi Community 🙂 👍
impossible to log into some websites (ex., Player.fm) using Google accounts
Most likely because you've turned Cryto Token support off in Privacy > Google Extensions.
there doesn't seem to be any way to see what is actually being blocked, it only shows the server name
You can press F12 > Network tab, to see what is being blocked on a site.
Do you see blocked requests to the sites you mention?
Try updating the EasyList by deselecting and selecting it again.
if it's just going to classify podcast audio sources as "ads".
Sometimes overly aggressive and too general rules manage to sneak their way into blocklists, but usually they are removed again fast.
The URL for the EasyList is: https://downloads.vivaldi.com/easylist/easylist-current.txt
You can search that (huge) file for the URLs being blocked. No mention of player.fm for instance. So it might be part of the URL.
Have you gone through all the troubleshooting tips?
https://help.vivaldi.com/desktop/troubleshoot/troubleshooting-issues/
After that, make a step-by-step guide how to reproduce your issue(s) in a clean profile of latest Vivaldi Stable.