After connecting over UDPCI the disconnect button no longer works.

#### Issue details
After connecting or attempting to connect over UDPCI the disconnect button no longer works. It will say 'disconnected' very briefly when you try to disconnect but it stays connected. Issue appeared after updating from the auto updater.
#### Version
Mission planner 1.3.70 Build 1.3.7277.34800
#### Platform
[ ] All
[ ] AntennaTracker
[ X] Copter
[ X] Plane
[ ] Rover
[ ] Sub

#### Airframe type
Any
#### Hardware type
Emlid Edge, but doesn't appear to be HW specific.
#### Logs
N/A

Start by reproducing the disconnect failure with a Mission Planner 1.3.70 build over UDPCI, including both a successful and attempted connection. Trace the disconnect flow and verify that the button leaves the vehicle disconnected instead of briefly reporting disconnection before reconnecting; no source files or tests are identified in the report.

Written by the indexing model from the issue text.