I have a Pixel 4 and multiple Sonos machines. I tried to log in to Pandora from the Sonos app and it wouldn't let me so I tried to log in to Amazon which also wouldn't let me so I tried Sonos itself through the app and that also wont let me log in. However, my app is connected to my Sonos system fine, it just won't let me log in from the app. It sees all of my machines and let's me control them, just won't let me connect to any music service or to my Sonos account. Everytime I try to log in through the Sonos app it just spins the circle for a long while then returns me to the home screen to try again, with the same result. I've uninstalled and reinstalled my Sonos app. I checked that I am able to log in fine through the website (even on my phone) and have confirmed that my email is "verified" in my profile. I also checked for updates after my reinstall.
So at this point I can't see any of my music. I'm at a loss but think I have to start with figuring out why Sonos won't let me log in.
Best answer by CassidyNY
Rebooting the Sonos hardware itself resolved my issue! I am now able to login to the app and music providers. I can't believe it was that simple, after all this time being frustrated! Thank you for your help.