Lip sync issue

Hello,

I have a problem since yesterday with the sound and the picture on my TV with Canalsat.
The issue only occurs on one channel and not on the others.

Previously, it used to happen on any channel, but all I had to do was change the channel to make it stop. Now, it only happens on one channel, and despite trying the same thing as before, it doesn't work.

Does anyone know what the problem is?

Thanks in advance :)