I have upgraded our own AP900s to the latest firmware 1.1.6 and switched on the Band steering,
Since then anything that connects to the 5Ghz disconnects - I cant see a pattern in time but it happens enough n a day to notice.

Switched off the 5Ghz and only use 2.4 and everything is ok again

The APs all use AD (server 2012 R2) for Authentication but this should be irrelevant as the 2.4 works fine

2.4/5 SSID both match roam is enabled on all APs

:?: :?: :?: