Port 443 Error when trying to sync store with CRM

[Andy Lead]

Hello, I'm new here so I hope I'm posting in the right section.

I have a store that's been working fine for almost a year. That store has an ERP/CRM (Dolibarr) module installed to sync sales, client, products, billing, etc. and since last week it's not being able to connect any more.

The error I get in Dolibarr is
[XXX.XXX.XXX.XXX]:443... Failed: Connection timed out
[XXXX:XXX:X::XX]:443... Failed: Network is inaccessible

The help desk from Dolibarr says that my server must be blocking the 443 port for the Dolibarr IP.
The help desk from the server says that 443 is used for secure and encrypted connections so the don't block any connections.

This happened suddenly and without any PHP, CRM, Prestashop, db, or hosting updates.
Is this a common error? Do you have any clue of what might be happening?
I'm very frustrated that none of the companies offer me a solution, and I am manually syncing each sale, product, price, stock update etc, which is very time consuming, and not viable in the long term.

Thank you very much in advance