You can try to close some advanced function of EAP Controller, such as Airtime fairness, Band steering, Load balance. I know from experience these functions may cause some connection issues of EAP...

Which information of EAP330 do you want to moniter? As I know, EAP330 just support public MIB (such as Mac address, IP address of EAP330), you can't find much information from it.

hanner74 wrote Model : If the corporate SSID quits the SSID is still being broadcast but you cannot connect, seemingly it does not try to authenticate. If the guest SSID quits you can connect, but...

such as http://tp-link.com

Actually, in the latest EAP Controller, you don't need to select Portal enable when you create a new SSID. When you configure the portal function, you can bind it to the specific SSID.

WBS510 have two antenna interface, so it can connect with two Antennas. But you can only connect with one antenna.