Odd temp problem on Orbi 850 network

My neighbor has an Orbi 850 and NG CM3000 modem, and they texted me with a problem. I am wondering if anyone has advice how to troubleshoot it if it happens again?

 

• It's an RBR and 2 RBSs. Last time I was there, I checked the RBSs, and they had 'Good' WiFi backhaul status.
• One person was in the kitchen - I measured there last week, good it had very good WiFi signals using a signal measuring app, about a week ago. The user had an iPad and laptop, working with both for about 2 hours there, all of a sudden Youtube gets very grainy on the iPad, laptop and iPad both showed network getting very slow, apps hanging - not a lot of detail on the problems. These devices likely connected to an RBS on the floor right above them.
• One floor up, another user was seeing no problems - they were connected to the router, being about 15 feet away with LOS to it.
• The person on the second floor ran the speed test from the Orbi app, and speeds were great and as they should be - 1187/177 for 1G/150 service, ping 12.98ms.
• In an hour, everything was back to normal in the kitchen - they didn't touch or do anything to the Orbis. They didn't even reboot the iPad/laptop.

- This doesn't sound like a Comcast problem or the other user/speeds would be affected.

- It likewise doesn't sound like a modem problem.

- To me, it sounds like the RBS the kitchen devices were connected to had a problem that connected itself.

 

I am going over briefly tonight, I will check modem logs/signals, router log for anything funny, make sure backhaul status is still 'Good'. They are on 4.6.9 or 4.6.14 as I recall. I was going to move them to 7.2.6.21 a week ago when I activated the CM3000, but everything was working fine so I didn't rock the boat.

 

Was there ever any kind of problem like this reported for the 4.6 FW - like devices flipping from 5GHz to 2.4GHz (as that might be what they experienced in the kitchen - funny it would be 2 separate devices though)? Ever heard of this type of problem? I have never heard of a partial network problem that corrected itself.

 

If it happens again, what would you do? I thought of:

- Check hop count on RBS debug page, make sure connections are accepted on the RBS/see which Orbi the devices are connected to

- Reboot network via router web page?

Of course if I am there I may see more specifically what's not working

 

Thanks for your ideas how to troubleshoot!