I had the exact same issues with 1920s and 2020s on older versions of vWLAN - drove me and the customers crazy and never had resolution from Adtran. Some customers had the problem, some didn't. it finally got better with later releases.
What OS are your clients running, im curious if it is windows 10 build 1903. As stated below it has been seen on certain adapters and PC's but others have seen it on equipment not specified below.
Safeguard on certain devices with some Intel and Broadcom Wi-Fi adapters
Microsoft and NEC have found incompatibility issues with Intel Centrino 6205/6235 and Broadcom 802.11ac Wi-Fi cards when running Windows 10, version 1903 on specific models of NEC devices. If these devices are updated to Windows 10, version 1903, they will no longer be able to use any Wi-Fi connections. The Wi-Fi driver may have a yellow exclamation point in device manager. The task tray icon for networking may show the icon for no internet and Network & Internet settings may not show any Wi-Fi networks.
To safeguard your update experience, we have applied a compatibility hold on the affected devices from being offered Windows 10, version 1903.
- Client: Windows 10, version 1903
Workaround: If you are using an affected device and you have already installed Windows 10, version 1903, you can mitigate the issue disabling then re-enabling the Wi-Fi adapter in Device Manager. You should now be able to use Wi-Fi until your next reboot.
Next steps: Microsoft and NEC are working on a resolution and will provide an update in an upcoming release.
Note We recommend that you do not attempt to manually update using the Update now button or the Media Creation Tool until this issue has been resolved.
Thanks for all the suggestions and glad to know I'm not the only one to have experienced this. I did not know about the Windows 10 incompatibility issue so thank you as well. When the issue arrises I am unable to pass traffic on any device including Android & iOS. It's very odd since they show a correct ip address and location in vWLAN, they just can't pass traffic. I just upgraded to vWLAN & AP firmware 3.3.0 so I'm hopeful this resolves the problem but will post back if it does not.
If it happens again under 3.3.0 I would try for some packet captures, I can't really comment on 3.2.0-HC stability as we are still on 3.2.0.HA for the time being.