After Power Cycling RBR / RBS 850 - Cannot Connect To Main Wifi - Only To Guest Wifi

Hello - I have a very frustrating issue where, after rebooting / power cycling my RBR850 and my RBS850s, nothing can connect to the main Wi-Fi - only to the guest Wi-Fi. I have looked all over the web and while I see a lot of people complaining of this issue and requesting solutions - I have not found any solutions to these questions or on any website including netgear.com

• I am at the latest F/W version on the router and satellites - v7.2.6.31
• I have approximately 70 - 80 devices connected at any one time (when the main Wi-Fi is working).
• My house is 3 levels (top floor, main floor, basement) and around 2,800 square feet (and yes, I realize a router and 4 satellites is overkill, but my wife and I work from home, and we need to ensure we have coverage)
• I have never had to move my satellites (and would prefer not to every time I have to reboot the router)
• When working properly - the backhaul status is good on 3 of the 4 satellites and one is poor - but everything is connecting and working properly on all the satellites.
• I do not have a hardwired / ethernet connection for the backhaul between the satellites and the router (mainly because I don't have either the access or ability to drill holes in walls and floors to run the cable)
• I am seeing a blue light on all the satellites; on occasion I do get a magenta light, and I simply reboot that satellite, and it comes back with a blue light.
• I have installed UPSs on all the satellites - attempting to avoid having power outages power-cycling the satellites and making me do this whole procedure again (and again, and again, ...)
• At this point - all my devices (cameras, security, ... etc) that have a hardcoded main network are down and unable to connect and I have changed all the other devices to the guest Wi-Fi so we can at least connect and do work.

The issue is really hit and miss as sometimes everything works great and the main Wi-Fi works, and all my devices connect automatically.

But more often than not - the connections cannot be made.

I have tried:

• Unplugging power for modems and Orbi devices.
• Power cycling the modem (Hitron CODA56 Multi-Gigabit DOCSIS 3.1 Modem using Xfinity) waiting 1 minute, waiting 2 minutes, waiting 5 minutes.
• When the modem is up (after each attempt at the different times) - I plug in the router waiting 1 minute, waiting 2 minutes, waiting 5 minutes.
• Then I go to each of the satellites, powering one at a time waiting 1 minute, waiting 2 minutes, waiting 5 minutes.
• I have done factory resets on all the devices and performed the same steps above.\

Recently I waited five minutes between power up and everything worked great, and I thought I finally figured out the secret - but this was short lived victory as the next time I recycled I ran into the same old issue again.

Due to this issue - I am considering a new mesh network as I need to have this working for my wife and I during the week.

Has anyone found the 'golden' solution? Is there a setting or settings I can try on the wi-fi configuration? I am open to trying anything. Please help - this is driving me nuts.