Even though I am signed into YouTube normally, I cannot subscribe to channels. I get "Want to subscribe to this channel? Sign in" and "Your session has expired" every time. Clicking "Sign In" (even though I am already signed in) does not help--the page refreshes and I get the same error. Additionally, I am missing the entire channel maintenance section when I click on my account (Your Channel, Switch Account, etc. Screenshot attached where you can see it missing), so I can't even sign out and sign back in without clearing site data in Firefox settings. Refreshing and uninstalling/reinstalling Firefox did not help. This is only happening in Firefox.