Have a recent problem with the sound cycling off/on approximately every 2 sec on Sundance (provider Philo). Consistent across 2 servers (1 win10 ethernet, 1 linux wifi) and 3 different clients (FireTV4K, Nvidia Shield, Nexus Player).
Also occurs on WE tv. Haven't checked every TVE channel, but at least some others are OK.
2020/10/18 14:29:53.318228 New diagnostic log submitted under bbc8a3bd-2b59-4036-a733-797611783af7
Have you tried watching it from their live feed in a browser?
If it still happens in your browser then it's their feed and not Channels.
Doesn't matter who your Cable or OTT Provider is.
And since they're both owned by AMC Networks, maybe their other ones have that issue.
Same seen on WE TV last night.
Just recreated on an ios device on WE TV, and submitted diagnostics
Took chDVRuser's advice and tried it from within a browser....separate PC on a different vlan. Saw the same behavior on Sundance there as with Channels. So it would appear to be a problem with the streams. Watching closely I also saw a slight glitch in the video stream every time the sound cut out. Interesting that it's gone on now for 3 days that way.
A couple more tidbits of info. The Sundance stream works fine from the Philo app or from the Fire TV Live TV app. Also, tried a couple of other AMC networks within Channels (AMC, BBC, IFC) and they are working fine.
WE TV looks like it's fixed. Sundance still with the same problem.
Sundance TVE finally fixed itself as of last evening.
Mark this as solved as a provider issue.
Still doing it for me
Yes...they broke it again. Started within the last couple of days.
Sundance doesn't see to really care about their TVE stream. Last time took about a week before it was fixed.
Still broken. Just sent note to [email protected]
Maybe get their attention if everyone sends in a problem.....
EDIT: To my surprise, received a confirmation with a ticket number. We'll see if anything happens.
I got a quick response too:
Thank you for being an Amc viewer and for reporting this to us.
We are consulting with Technical about the issue and apologize for any inconvenience this has caused.
Thank you for your patience as we get this sorted out.
Charmaine
Amc Networks Viewer ServicesI got the exact same email response 
Wow....looks like they are all fixed (at least at this moment 
)
I was recording something on AMC and am getting the same problem (sound dropping in/out every 3-4 seconds or so).
Looks like it's fixed now....
For future reference, here's the AMC link to report a problem
http://support.amc.com/en/support/tickets/new