bug: MAVLink Endpoints not saving

[drewfowler]

Bug description

I have a cm5 running 1.4.2 on an io board where the /dev/serial0 is connected to a cube orange.
I am trying to create a serial mavlink connection to the cube orange.
When I try to create an endpoint, it returns to "No endpoints available".
When I click "Create Endpoint", an empty message bar at the bottom is displayed with the close button.
I can sometimes get a UDP endpoint to save.

system_logs.zip

Steps to reproduce

Enter a Serial mavlink endpoint with "/dev/serial0" as device and 921600 as baudrate.

Primary pain point(s)

No response

Additional context

No response

Prerequisites

• I have checked to make sure that a similar request has not already been filed or fixed.