Orbi RBR850 unstable/DHCP assignment issues after reboot

Currently have about 60 devices online with my 963 series and v.15 FW. Not seeing any DHCP issues. 

I have my two RBS assigned IP address reservations and also have a smaller DHCP IP address pool size as well. .100 to .200. 

Also IPv6 is disabled on v.15 FW as well as there is a known issue with this version of FW that breaks IPv6. Thought I don't need IPv6 as my ISP doesn't support native IPv6. 

System is working well for me on v.15. Longest time run with it was just over 30 days: Share your Orbi 350, 750, 850 or 960 series system UpTime | NETGEAR Communities

Someone else with the 850 series seeing a long time running with this FW version on there system: Share your Orbi 350, 750, 850 or 960 series system UpTime | NETGEAR Communities

If you don't think you can get v.15 working, then revert the system back to v.21. Thats was considered the most stable FW. 

Dws62001 wrote:

I have had this same issue for a couple years across several FW versions. I upgraded FW months ago, currently on 7.2.7.15 and have the same exact issue. It is absolutely maddening that netgear can’t handle network devices. The amount of time it takes to get this stuff back online is rediculous. I am currently running between 86 and 96 devices online at any given time. On a reboot it can’t reassign the IPs completely leaving many offline for days requiring yet another reboot, again, and again, and again until finally everything takes. And after doing some reading it appears newer routers like the 960 do the same thing with lots of devices. Next step is trash and buying another brand. Please help fix this