RBR50 - Massive connection issues, wrong password, dropped devices, etc

Morning collective mind,

Having an issue that has now spanned two seperate RBK53 systems.  Late last week I started to have issues with my FireTVs saying that there was no network connection, a simple reboot of the stick resulted in fixing the issue.  By the weekend my children were complaining that their Xboxs kept dropping connetion.  I rebooted the RBR50 and things were good till midweek.

On Wednsday my daughter mentioned that the refidgerator had lost connection and she couldn't access the shared family calander (It's a Samsung with the large LCD built in, kids use it to see the plans for the week).  I rebooted the fridge and it connected without issue.

On Thursday I had more FireTV connection drop issues.  One Xbox, my phone, two Eccos and one ecobee thermostat could not connect at all.  My phone (Android) kept trying and would report "Incorrect password" while my wife's identical phone had zero issues.

I did some research that evening before saying screw it and ordered a new RBK53 system for 8am Amazon delivery.  The old system was 3 years old and I thought that it might have been at the end of it's life.  Got home from the office and had the new system up and running in just a few minutes.  Setup the SSID and password to mirror the old system so all devices would just migrate over to the new hardware.  Everything was perfect, just like new again.  Kids were streaming on PCs, three FireTV 4Ks streaming, tablet streaming music, Eccos and Hue lights working, etc.

Woke up this morning to my phone not having wifi.  Asked my bedroom Ecco for the forcast and got the good old red ring and her saying "I cannot connect to your internet right now."  Great!  Once again I'm back to having some things connect and work without issue while others report "Incorrect password" and others don't find the wifi at all.  Which devices work is also completely random; some Eccos, two of the Ecobee thermostats, two phones, one or two FireTVs.

I've tried just about everything I could find on these forums; changed the router over to AP, installed the 2.5.1.8 firmware, etc.  Hardwired PC connections to the modem (It's wifi is off) in the office are perfectly fine as are all hardwired AV gear and the Xbox/PS4 in the theater so it's contained to the Orbi system.  All hardwired items in the house terminate at the modem in the office via gigabit switches.  I'm just having a hard time convincing myself that whatever is causing the issue has spanned from a 3 year old system to a brand new one.

Any ideas?