I generally use Firefox ESR and don't have any problems. (Note: if you use Slack things are a bit broken sometimes in Firefox ESR. In fact, there's a notice tha

I generally use Firefox ESR and don't have any problems. (Note: if you use Slack things are a bit broken sometimes in Firefox ESR. In fact, there's a notice that they'll stop supporting this browser on March 1. I haven't noticed any other broken sites though.) Last time Firefox wouldn't connect to stuff (Google sites) even though every other browser would (March 21~22, 2017, but I think that was a problem that didn't affect the whole world), the workaround was very similar to the one discussed in other comments here: disable network.http.spdy.enabled and network.http.spdy.enabled.http2 (Insert snarky comment about feature creep and questionable frontend engineering here)