Help with broadband / tv please/ Orbi Mesh

[DanMen]

I’m sorry but I have absolutely no idea what that even means!

[WSH]

Somewhere in the setup for the Orbi there will be a setting for Internet Group Management Protocol (IGMP).  If it is disabled by default that may be your problem.  I'd try turning it on (and also turn on the "Snooping" setting associated with it). 

[DanMen]

Can’t see anything on my Orbi app for this. I could call netgear support to ask about this. Thanks

[WSH]

It may be built-in and enabled by default then.

Just a thought.  As Licquorice said, it wouldn't explain some channels working and not others anyway.