RBR750 Guest network intermittent connection issues

As of February 2021, the problem is still with us.  Worked with support, and they eventually said to replace the units.  The same problem still happens with the new units (no surprise to me).

Equipment:

• RB750 Base unit
• RB750 Satelite unit - wireless connection to the base unit, signal is: good
• ISP connection: Wireless from the house to the local node (yes you read that right, I have a dish pointing to the local node which is powered over ethernet), IP supplied by the ISP.  Conection to the RB750 is a normal CAT6 cable.

Symptoms:

• Guest network periodically stops talking to the internet,  then starts talking again (annoying as all get out when watching a movie).
• WiFi connectivity remain strong
• Guest network time: Always
  Note: this can only be set in the mobile app, support did not appear to know this
• Main network continues to connect to the internet without issues
• Wired connections on the router continued to connect to the internet without issues
• The satelite is connected to the base wirelessly.
• The wired connections hung off of the satelite continue to talk to the internet without issues.

Things Tried (none of these fixed the issue):

• Power cycling the router
• Power cycling the satelite
• Changing the WiFi channels (I also have an app on my phone which sniffs out nearby WiFi signals, so I can find the channel with the least interference).
• Checked the firmware - is the latest
• Reflashed the firmware for both router and satelite (done at the direction of support)
• Full reset to factory setttings, reload saved configuration
• Full reset to factory settings, minimal config to make it work in our environment
• Replaced full system (done at the direction of support, saying it was a hardware problem)

Final test configuration:  old router in place of RB750, RB750 in AP mode. This configuration is not sustainable because the old router does not have the reach needed on its own for the guest network.

My guess (and it is just a guess) is that the problem is likely in the code which manages the guest network time.  I would say it is an easy fix, but I have been in the software business for (mumble) years, and know that is rarely the case.

I  have not found a way to know this is truely sent to engineering, since I cannot get any sort of bug/ticket/problem number for the request in engineering. It also means I cannot check on the status of the problem.

sigh...