We have recently reconfigured one of our SSID's so that users are assigned a group policy that assigns ACL's and VLAN depending on if the user is a Staff member or a Pupil. The RADIUS functions are provided by Cisco ISE.
Since making these changes users are now experiencing an issue whereby their device shows as connected, it has an IP address in the correct VLAN but it has no connectivity. We are unable to ping to and from the device and within the dashboard it shows as disconnected.
In timeline we see "802.11 REASON (CODE 34) Missing Acknowledgements" which has the definition of association denied due to excessive frame loss rates and/or poor conditions on current operating channel, however our channels show as low utilization.
We are currently only seeing this behaviour on the 5 GHz band and with iPads however they do make up the majority of our devices.
Has anyone else seen or experienced this issue or can suggest troubleshooting?