I've observed this mainly on iOS 11.x devices and some Android devices running Oreo. This has been ongoing for months. The "fix" is to reboot the AP, or any sort of change to the AP that will reset the radio (such as modifying channel-width or client load balancing and such).
I'm using the MR42 platform.
I've run several pcaps when the issue occurs, and what I see is associate probes, probe responses, authentication completes and association is successful. The following is a series of client RTS and AP CTS packets. But that's it. No data. The client just keeps asking over and over "Ready to Send" and the BSSID will respond with "Clear to Send" but the client never sends data.
Because I'm running NAT mode with Meraki DHCP, a DHCP address is never obtained because absolutely no data is ever sent, even though the client is associated.
I've been going back and forth with 3 different Meraki support engineers on this.
A couple things I've noticed:
I have 2 old iOS 9.3.5 devices that don't have this problem at all. Only updated 11.x devices.
When I run into an AP that is acting up, I will walk around to a different AP and it will associate and work fine.
As mentioned before, any sort of reboot or state change or radio reset on the AP will temporarily fix the problem.
So...anybody run into this?