@administrator, did you by any chance start blocking https requests based on User-Agent a few weeks ago, or tightened preexisting rules?
I had been unable to access with abrowser for all this time, and could only access over text-based browsers over tor after my home IP got blocked. at first I didn't realize I was getting an unusual error; then I thought it was some abrowser upgrade that broke something; then I upgraded another machine that still worked and it kept on working; then I verified all TLS- and abrowser-related files on this machine and found nothing unusual; finally, I realized both browser profiles in which it failed had a modified User-Agent (to have GNU in the operating system name, rather than the misnomer Linux), but the one in which it worked didn't. once I disabled User-Agent overriding, it started working again. so now I configured the browser to lie about the operating system name when contacting gnusocial.net, and I'm back!
if my diagnosis is correct, could your User-Agent blocking rules please tolerate GNU as the operating system name? TIA,