Don't know if this is your case but I was getting freezing channels a lot almost every channel after 10 seconds would start freezing

So this is what I did to fix it.

1. Reset the Mac
2. Unplugged all 3 items: Modem, router and Mag (box).
4. Turned on modem and router at the same time then turned on Mag (box) after about 10 seconds

Waited about 4 minutes for Internet to be back on again and then entered the routing number for that Mac.

Tried watching TV and no more freezing.
Freezing is gone.
Hopefully it lasts but it's been over 20 hours and still running smoothly


Hope it helps
Good luck!