Comment by amanzi

Same here, using Firefox 129.0.2 on Windows 10. uBlock running and I also have Firefox's "Enhanced Tracking Protection" turned up to max.

I did have issues with YouTube recently - I was getting some of the same symptoms described in the Reddit post. But tracked it down to me changing my user-agent to Chrome, which I had forgotten about. This was also causing issues with reCaptcha and Cloudflare-protected sites.