UPDATE:  If I remove the focuser from the configuration, the Powerbox Advanced will connect. As was mentioned in the link ouioui01  provided, the port name is  truncated and that truncated name is saved, so it looks like it has to rescan to get the correct port name.

If I add the Pegasus focuser back in, then both the Powerbox Advanced and Focus Cube II will not connect.

Very frustrating.