Here are also problems with Chromecast.
I have one AP11, version 2.0.1.
Android phone (Xperia L1) and the Chromecast (2015) connected to the 5GHz network. The 'Visibility And Control' setting is set to 'Application activity summary'.
Sometimes I have to press the Cast-button at least 5 times or restart the app, i.e. Youtube or Netflix. With my work phone (Samsung A8) or the wife's phone (Motorola) I am getting the same experience.
Something (the AP11?) is blocking broadcast/unicast/multicast traffic?
I'm thinking of getting two AP11's more, but if this issue is not resolved, I will have to reconsider.
A full-fledged modified IAP firmware is also welcome.