To add to the warnings about containment.  While it is generally illegal there are specific circumstances where you may be able to use it.  If everything and everyone in the building is subject to company policy you could make it a company policy and...

Check that you followed every single step of the 9800-CL VMWare deployment guide very carefully - go through it again step by step. Also refer to https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/technical-reference/c9800-best-practices....

You can also get detailed debug logs from the iPads.  You'll need an Apple Developer subscription and then download the WiFi debug profile from https://developer.apple.com/bug-reporting/profiles-and-logs/?name=wifiStrangely I don't see iPadOS there s...

I don't know the answer but you might want to take a look at this really thorough answer yesterday:https://community.cisco.com/t5/wireless/bonjour-service-mdns-for-wired-and-wireless-devices/m-p/5078762#M270725

Refer to TAC recommended link below for current recommended software version.  Depending on what subordinate APs you're using you should ideally be using 8.10.190.0 (check compatibility matrix if you have older APs).