[plongeur.com]

I think you meant 'follow channel moderation rules" but it was sete up to yes.

Anyway i ended up reversing the way i was doing it :
At first i clicked "deny all" and tried to give access to my "pros" group.
Now i reseted the settings and set "Can View Topic Content" to "no" on all other groups than "pros".

This way it seems to be working, the only issue i have left is that my reguler users have an erro rmessage saying that they cannot access this page when they try to go in the channel and i would rather they see an empty channel with just the notice.
This is what they saw before and it was better than an error message.