I have this weird behavior that out of my 2 EAPs, one of them just doesn't discover chromecast devices consistently while the other is perfectly fine. They are all wired to the same switch and it is the same SSID with the same settings. It doesn't matter if i disconnect or reconnect or the device.

Connect an iPhone to EAP1 and it will discover my chromecast devices everytime, when that same iPhone connects to EAP2 it will discover 1 chromecast device or none while other times it finds all chromecast devices. 

Connect an Android to EAP1 and it will discover my chromecast devices everytime, when that same Android connects to EAP2 it will discover 1 chromecast device or none, what I found was disabling randomized MAC setting on the phone helped with discovery for a short period.

What is causing this? is it because the phones are switching between EAPs and possibly changing MAC addresses eventhough it is the same SSID on all EAPs?  This does not seem to be the case as my logs show the devices roaming correctly.

I setup WLAN groups for each EAP so that I can have different SSIDs, I have a SSID for my lights and don't need them roaming to EAP2 etc. However I have the same SSID setup on both WLAN Groups so my mobile devices do not change SSIDs. This also does not explain why sometimes mobile devices are able to find chromecast on EAP2.