I had the issue with client match on and client match off.
I factory restored, then just created 1 network. Just SSID/pass
Very simple config.
2 of the IAP-135's came from another system and I used the factory reset button to reset them before adding them to the system that already had a perfectly functioning IAP-135 as a controller. The issue began after i added the 2 additional access points. They all show up and everything works fine EXCEPT clients get dropped and do not automatically reconnect.