WAC540 Apple Device Issues

I have a WAC540 access point and am having issues with what seems to be only iOS devices (Iphones and Ipads). The symptom that they experience is random HTTP load and connection issues. For example they will experience a web site that will partially load and then stop. Sometimes reloading will completely load the page, other times it will not. Sometimes pages will not load at all, while on other non Apple devices (e.g. a Windows laptop) it will load just fine. Can't put my finger on any sort of pattern so far but it just recently seemed to become a problem.

The AP is running firmware 9.5.2.4 and it says there is a new version available which I plan on upgrading to this weekend. I have 2 WiFi networks configured. One configured for 2.4 and 5ghz and the other only 2.4 with the latter only being used for iot type devices. All user clients connect to the first network and all Apple devices are using 5ghz with some on Low channels and some on High.

Just trying to figure out how I might best troubleshoot this. Any suggestions welcome.