WAC 510 - Flaky Connectivity and Behavior - Is it failing?

Hi, I have a WAC 510 that has been behaving strangely for several months now.  It is located in the attic above the garage in an area that can be quite hot during the summer, but I'm not sure that is the problem.

Its main purpose is to provide connectivity for a couple of Nest Outdoor Cams that are on the front of the house in the eaves above the garage and on the side of the house away from my other WAPs.  It also provides wired connectivity to an Arlo hub that is positioned in the same location to support a couple of outdoor Arlo cameras.

The symptoms are as follows:

1. For the last several months, I often get an error message "NETGEAR Account Alert: Device Command Failure" for that WAC 510, with the failure reason given as "The device configuration has failed".    But even with that message the device seemed to be properly supporting its clients.

2.  Today my Insight app was showing that WAC 510 as disconnected, but on the device itself all the indicator lights showed proper operation, although when I logged in from my desktop there showed no clients.  

It is one of my older APs.  I wonder if it is starting to fail.  And I am wondering whether there would be another AP that I could replace it with to go with my BR500 router and my other Netgear APs (WAC 510s and one WAC 540).