A "restore hardware defaults" from the ProxyAV's serial console is required to resolve this issue. Here are the commands to restore the ProxyAV to defaults:
1. Wait for the "Press any key during 5 seconds to access Boot menu" message and press <enter>
2. The following menu will be presented:
a) Restore hardware defaults
b) Restore boot
3. Press <A> to restore hardware defaults
At this point you will need to reconfigure the ProxyAV.
This issue will be fixed in ProxyAV OS 18.104.22.168, if and when that becomes available. This issue does not occur on ProxyAV OS releases 2.x, 3.1.x, and 3.2.x.