here's a short report:
tried to install KUAL BBB filters but it won't solve my problem.
next i installed WPA Enterprise, this is the config i wrote down:
I also connected the AP to the internet now but it still refuses the connection, all other devices still run perfektly with and without internet connection ...
here is also my hostapd and dnsmasq config, i use to run the AP, it should be ok so far
Spoiler:
hostapd.conf
dnsmasq.conf