Hi Andy,
Thank you for your suggestion.
The AP firewall is enabled and when I added WLAN ACL rule for any source/destination the Android phone connects to the internet no problem.
But the RF scanners and industrial tablet still can't, even when I add the ACL rule with their respective IP addresses.
I agree it is a matter of the firewall settings either with the AP or RF devices.
I have asked our IT manager to confirm our firewall settings for AP 7522 but with other devices connecting to the internet using the AP radio, it may be an issue with the RF firewall unless there's an AP firewall policy on limited external access from RF devices?
I am also going to consult our RF device manufacturer for advice.