WLAN access rejected: incorrect security

Hi All:

Got a Nighthawk MR60 with 2 attached MS60s with ethernet backhaul. Running 1.0.6.102_2.0.45

The MR60 is in AP mode, and once every 2 days or so Ill get a bunch of the following messages in the logs 

[WLAN access rejected: incorrect security] from MAC cc:50:e3:44:ed:8a, Monday, Dec 21,2020 11:07:01
[WLAN access rejected: incorrect security] from MAC 50:57:9c:86:fc:18, Monday, Dec 21,2020 11:05:54
[WLAN access rejected: incorrect security] from MAC a8:1b:6a:67:65:52, Monday, Dec 21,2020 11:05:39
[WLAN access rejected: incorrect security] from MAC a8:1b:6a:67:65:52, Monday, Dec 21,2020 11:05:19
[WLAN access rejected: incorrect security] from MAC cc:50:e3:44:ed:8a, Monday, Dec 21,2020 11:04:57
[WLAN access rejected: incorrect security] from MAC cc:50:e3:44:ed:8a, Monday, Dec 21,2020 11:04:27

These are all devices which are already connected to the WLAN. 

At the same time, latency on the Wifi jumps from 10ms to 250ms, and bandwidth drops to less than 3Mb/s

When I reboot, it clears the issue for a few days. 

Any ideas on where to start?

-chris