Compare the behavior of the apps when connected directly to the router. Does it work then? If not, the failures might be caused by restrictive firewall settings on the router. The EAPs don't block ports needed for iCloud etc.. Ports which need to be open on your router on egress for iCloud services are TCP ports 25, 80, 443, 587, 993 and 5253.

Ah, great. Maybe it was caching in the browser or something weird.

Hi @JeremyHiggs, what do you mean with »WiFi drops«? Does the client lose WiFi connection to the EAP completely? Or do you mean the audio stream has packet loss?

JeremyHiggs wrote

the phone appears to be no longer connected to the wifi network, as the signal indicator in the status bar changes to 3G/LTE.

This is normal behavior of any phone if the WiFi signal's quality drops below a certain watermark (about -80dBm).

Just turn off mobile data and try again. Expect packet losses if the WiFi signal is too weak - then only a re-configuration of your WiFi network can help.

The decision to switch to 3G/LTE is made by the iPhone. If you don't experience such switch-overs with Zoom software or over a VPN, then there is some other cause forcing this switch-over. I have no iPhone, but on my Neffos running Android I can decide for every App if it should switch over to 3G/LTE when the 3G/LTE signal is more powerful/has better quality than the WiFi signal.

Just disable mobile data or try to set FaceTime to only use WiFi if possible. If this works flawlessly then, it's not the EAP. If it does not work flawlessly despite standing beside the EAP, then the problem is with the EAP's WiFi signal. But in the latter case connectivity problems also should happen with Zoom software or over a VPN, too.