Stumped - Random disconnects

I've run into an issue that has me completely stumped, and the provider as well.

We are getting random disconnects that are brief, acts like high latency, no DNS resolution. Solves itself in 30 seconds or less but it's causing havoc to always on connections.

We have used three different modems, three different routers.

Every time the interruption happens, the CMTS hop is a Private IP. Running extended testing, the CMTS hop switches consistently between a public and private hop at the CMTS. When a private IP is the CMTS hop it does not always cause the interruption.

When I hook a laptop up directly to the modem, using DHCP or our static block we never get the private IP as the CMTS hop.

When we use our primary router, Peplink Balance One, we do not hit the private IP for the CMTS while using DHCP, but we do when we use our static block. We have factory reset this device as well with the same result.

We used a factory reset Sonicwall TZ with exact same results as above.

I rolled a pfSense install today with the exact same results as above.

This is going on 4 weeks now, and started out of the blue in the early morning. Provider does say maintenance was performed that night. Happens 24/7, frequency of the disruptions are random.

Provider did have some signal noise issues, which they state they have cleaned up over the past 10 days.

Any advice or suggestions would be appreciated greatly!