Yeah, seems like Unity 2020 LTS is really buggy when it comes to WebGL, according to forums? I admit I don't have any experience in web development, so I don't think I can fix a browser specific bug anytime soon.
Also...DING DING DING, we have a winner! Yes, it's Gout, ohhhh and you REALLY don't want to suffer a gout attack, trust me.