HA !
So that is exactly what I was referencing in my first response lol
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So basically that group policy you have on the access control settings for that SSID is going to have false positives as you've clearly seen.
I have to deal with this myself, where it thinks that a MacBook Pro is an iPhone and it blocks it. I probably get a client a day for this type of thing.
Two solutions:
1. remove that feature
2. use EAP-TLS with certificate/machine based authentication and then remove that feature