RBE971 AP: Wi-Fi drops, wired stable, QCN9224 SSR & 6GHz fatal errors

What is the brand and model# of the Cable modem?     
Motorola Docsis 3.1 MB8611

What all devices are connected to the system? 

A mixture of normal home devices.   Windows and Mac systems, phones, a printer, apple TVs, a thermostat.    The Satellites and a couple of the devices I have given (internal) static IPs outside of the DHCP range.     I have one or two things on the IoT network. 

Is IPv6 enabled on the RBR?   
No

Happens with out the RBS turned ON? 

Have not and will not try running without the Satellites for any length of time waiting for the issue.    That is not really an option.    

Size of home in sq feet please? 

2500 ish not including garage/patio/exterior.   I know this question relates to if the satellites are stepping on each other/placed too close.   They are mainly in opposite sides of the house although I have tinkered with placements here and there.    The furthest one is on the complete opposite corner of the house with many walls in between it and the router and is usually daisy chained, it was obtained to try and improve fairly poor performance in the farthest area away from the router.     Changing the position of the router in relation isn't really a viable option.    

Try downgrading FW to see if this issue continues? 
The netgear support/firmware downloads page is 404.    Where are older FW to obtain?   The reason for posting was in the hopes that netgear support was going to post an answer to Travisivart's questions

Channels used on the RBR? 

For 2.4GHz - auto.   IoT network 2.4GHz only.    For 5GHz I have tried 40, 44, 48 and even tried a couple of the DFS channels as well just to see if anything changed.    The problem has persisted across each and no I don't live near known radar sources.       
I have tried 20/40MHz Coexistence on and off.   I normally have it on.    
I have tried Long Preamble and Auto.    
I have tried MLO 240 on and off.
No change in symptoms when the event occurs.    


Has a factory reset been performed since last FW update? This should be performed if it hasn't been yet. 

Factory resets were done on the Satellites but not on the RBR.   Frankly that is an annoyance and one that shouldn't really be necessary as a default go-to "have you done this yet" troubleshooting step after any/every firmware update on such an expensive piece of gear just in the off chance that solves the problem.   A problem with very similar symptoms to travisivarts.     If the problem can be solved via a firmware upgrade/downgrade or another mitigation in the settings as travisivart asked then I'd rather save factory reset as a last resort.    And tbh If I reach that point then I'm about one repeat of the problem away from ditching orbi/netgear forever for something more reliable.