Solved: Youtube Subscription Playback Issue
I was getting an odd error with Youtube video playback today on Firefox. When trying to play youtube videos from my subscriptions (and only my subscriptions) I got an error stating "This video is restricted. Try signing in with a G Suite account" even though I don't use a G Suite account. Did not occur on other browsers.
I noticed that F-Secure had a firefox update but it would not install correctly until I did a full system restart.
After the restart was completed the browser extension installed correctly, and I the playback issue has been resolved.