Problems accessing HTTPS domains on BSNL Bharat Fiber Broadband

I am unable to access this forum from my fibre connection. It is showing certificate error. But it's opening fine on ADSL Connection.

hmm. that should not be happening. would it be possible for you to check in another browser? but that should not change anything. this is hard to investigate.

I checked with 3 browsers. Opera, Chrome & Brave. Same problem.

so which connection is giving you the problem? jiofiber?

Bharat Fibre

hmm. hopefully someone else can confirm the same. forum is on cloudflare ssl strict option. makes no sense unless bsnl is doing something fishy at their end.

All https sites are giving this error. Not only this forum

Have you not updated your OS (windows?) with latest updates?

Hmm. From what I remember reading chrome relied on windows for certificates but Firefox used its own database?