I noticed this apparent misbehavior recently thought it would be good to write it up. I love DX Lab Suite so much, thank you Dave!

Summary:
Commander fails to set mode when selected in mode panel following mode change made from radio.

Replication/Explanation:
Change mode from DATA-U1 to RTTY (To tune amplifier)
   Observe that Commander mode panel updates to reflect mode change to RTTY
Attempt to set mode to Data-Uw from commander mode panel.
   Observe that Commander mode panel updates to indicate mode change to USB-D1
   Mode does not change on radio.

Workaround:
    Change to any other mode from Commander mode panel, then change to USB-D1 is successful.

Note: I was unable to replicate this with other mode combinations.