UART 1 baud reverts back to 57 when FC reboots

ArduPlane Plane 4.1
1

I can set SERIAL1_BAUD to 115, write params, refresh them and it has definitely changed to 115. But after power cycling the FC (Matek F405-SE) and loading the params, it has reverted to 57.
AP 4.1.7 running on Matek F405-SE.

Does anyone know what can cause this?
Thanks,
Oliver.

2

If the parameter set you load sets the parameter back to 57 …

3

The parameters are downloaded from the FC into Mission Planner, so the values should reflect the values stored in the FC. For some reason the baud rate of 115 isn’t being stored or is being overwritten with 57 when the FC boots up.
Are there any conditions in which AP 4.1.7 will override the baud rate with a default?

4

It seems that the baud rate is ignored and overidden by AP based on the UART protocol selected. It would be helpful to make a note of that in Mission Planner.