Why does it reset the connection to the server?

Question

Computer networks

After adding a certificate to one site, the site itself stopped working. Just resets the connection to the server. Others are doing great. MTS provider, does not log in from a computer, but logs in from a mobile (also MTS). Tried through TOR - comes in. What could be the reason? Really the provider blocks this certificate? Or is it something sewn into my hardware? Very strange situation, the certificate is taken here . If anything, no uncles set up my computer and did not sew anything in there. What could be the reason?

Answer 1

I noticed such garbage in Git - it doesn’t want to work through https lately. It works through ssh. And it is on MTS.
Maybe MTS tries to replace certificates sometimes?
I did not understand the reason - because. there is an alternative internet. On it with https Git works fine.