XiD-P box is unable to connect to main DVR

I have been having a lot of trouble with my secondary DVR boxes in my home. When I first installed the system (1x XG1v4-A, 2x XiD-P) a few months ago, I was able to get all the TVs working pretty well. It did take several restarts of the boxes, both my main box and the secondary clients to get everything to recognize one another, but it did work. Over the last month or so, however, I've noticed more and more issues on my bedroom TV (one of the XiD clients) and it has gotten to the point where I cannot use that location at all.

When I turn the screen on, the picture is usually frozen, oftentimes with a message of "We're not able to connect to this set top box" (Error RDK-03053), and prompting me to restart the box. When I restart, sometimes it will connect (after usually about 10 minutes or so of the "Connecting..." screen) but it will come up and start pixelating/freezing again within 1-2 minutes, and I am back where I started. Many times when I reboot the box it fails to connect and takes me to a screen prompting me to restart again.

I have rebooted many times, I have performed system refreshes, I've tightened cables, switched out the coax cables for different ones, switched out HDMI cables for new ones, and even swapped the XiD-P boxes -- taking the one I have in my basement and putting it in my bedroom location. Like I said, it had been working when first set up, but it has gotten more and more problematic to the point where the TV is unusable now. I haven't made any wiring changes, moved any of the TV's or boxes, so it's strange that the degregation has occured.

Also interesting -- my main box always seems to be working properly in terms of displaying content, however there does seem to be some wierdness in communicating back to Comcast. When I go to the xfinity site or app, and it shows the status of my equipment, it will occasionally show a "green dot" next to my main box, most of the time it shows no dot. When I try to do something like "Identify this box" it will often fail to send the signal to the box. Also, when I do troubleshooting from the app, it usually tells me that my main box is offline, despite not seeing any isses on that TV itself.

Not sure what to do at this point? Has anyone gone through similar issues? Does it sound like a signal issue?