TV artifacts on many channels

Hi everyone, i am experiencing TV artifacts (i.e. pixelization, stuttering pictures, sometimes a black screen) on 22 channels. I have tried the following:

1. Restarting and refreshing the system (via the "help" settings on the STB)

2. Swapped the location of the primary STB and its satellite box (still connected to the same coaxial outlets, just switched which box is connected to which outlet)

3. Verifyed my cable modem is good (no issues with the internet, but did check the signal levels as i did buy my own Netgear modem)

4. Turned on the "check cable signal" feature from Comcast Labs (shows "green" Good signal level whenever i check it, even on a bad channel)

5. swapped out splitters (only using a 1 to 2 splitter)

6. Powered down the MoCa network i have, just in case it was messing it up

7. Changed all the video settings within my TV and the STB

8. shut down internet completely, refreshed the X1 system (using the feature in the help menu), then powered up the internet once the X1 boxes were back up

So far, nothing seems to help , though, when i watch those same channels via the Xfinity Stream App on my Roku, the channel comes through without an issue, so it seems like it's an issue with the cable signal (though I am not 100% sure) as the channel seems ok. I just not sure why the cable signal would be the issue if the remaining channels come through without issue and the internet is working just fine.

The last thing I am going to try is to completely remove the splitter to see if it makes a difference, but that solution will not work for me long term as I need the splitter for my MoCa network and i have been used 1 to 2 splitters with all sorts of Comcast STB's for many years without issue.

Any suggestions? Thanks

Ankur