Just wanted to add that I tried viewing YouTube comments in private mode and with the extensions disabled and was unsuccessful. I am able to view YouTube comments in other browsers such as duckgo, opera, and Google Chrome.

This isn't a fix, but here's a workaround:

Copy and paste the video URL into the Opera browser to view YouTube comments. Be sure to enable the ad block option in the Opera settings.

One nice thing about using Opera is that you can scroll down the comments and view the video at the same time (something that you couldn't do in Firefox when it was possible to view YT comments in Firefox).

I also tried this workaround using the DuckDuckGo browser but had to seek an alternative when I started getting disruptive ads while watching YT videos.

i have similair bug in the UI for comments but mine has the work around of, turning my Pixel horizontally, then click comments , and it loads. Otherwise if i goto view comments, sometimes they simply will not load.

i also am almost never logged in though. And because of that i cant comment anyway.

I seen amazon has similair sorta principle idea with trying to read reviews where i am. Unless people are logged into amazon account, they restrict you to viewing 3 currated and truncated reviews and no more..

Maybe this is what youtube is going for, or maybe unrelated entirely. I think few people have the time or knowledge or attention span to learn how to diagnose these things

No one else is experiencing this problem so there's no incentive for finding a solution. I'll try posting to another forum as this one has turned into a ghost town.

Firefox for Android always had limited functionality compared to the Fx desktop browser and compared to other Android browsers such as duckgo and opera. Aside from security updates, the Fx Android browser seems to have been abandoned by the developers.

I have the same issue pending resolution. Though I think it's not a vital or essential issue so it is less likely to get picked up and worked on unfortunately. For me viewing on mobile via desktop view shows the comments, but not as optimized for mobile screen format.