Users disconnected

Hello,
I have installed Jitsi in own server and since last Tuesday, most of users who are connected from a specific Telecom operator are disconnected after few seconds. The users using the two other operators are not disconnected.
At first I taught that it was an issue with this operator and our data center, but when I changed the data center the problem persists.
When using meet.jit.si server the problem didn’t appear.
Thank you in advance for your support.

Hello, any help on this issue?