Hi

What version number of Firefox for Android do you have installed on your Android device?

Thanks for your response Paul. Not completely clear about the version, but I'm guessing it's 123.0.

Do you have a lot of adblocker add-ons? Maybe music mode for YouTube? I had multiple add blockers as well as the music mode for YouTube and the videos wouldn't play. Some add-ons will work for some sites and break others. You gotta find which sites work with which so you can disable the appropriate ones for those sites

Thanks Dannyb, But it doesn't seem to help my problem. I don't have many ad-ons, (and was a bit shocked to see that I don't have any ad-blockers on my phone now). Most of the music I hear on YouTube is part of info video content.

What add-ons do you have installed in Firefox for Android?

Thanks and apologies. I did find I have Adblock Plus installed. I disabled it, then restarted the phone, and videos seem to run. But does this mean I have to completely do without an ad-blocker in order to see videos on Firefox? (After a few days of using Chrome, it is more than a relief to get back to the more relaxed format of Firefox).

Instead of using Adblock Plus, you may want to try the alternative uBlock Origin.