Hi!
This is a nice coincidence.
We talked 1 hour ago about a problematic and "maby" you are a perfect "laboratory rat"
Sure.... I not see your situation (without mcc file) and normaly i would ask you some questions and try to rebuild this myself.
BUT: This sounds extremly as a older problem we currently try to rebuild.
If you like you can help us here.
Please make the follow Steps for us:
1. Save your MCC File and also the Board settings ( MFMC File) in the current state ! So the state where you got the Problem !
Put this 2 Files to a save spot ( other directory/harddisk/UsbStick whatever) so you NOT overwrite them .
2. Open Mobiflight while the problematic Arduino is connected.
3. GEt into Device Settings Tab.
4. RENAME All your devices on that Board.... For this Testing give them Names with the follow Logic:
A ) Use NO Spaces and NO Symbols like -_:;,.+*/"&§/$) and so on..... So Only A-Z or 0-9 .
B ) USe NOT more then 4 Chars .... So call them for example A01 A02 A03 and so on.
5 Not forget to UPLOAD the renamed Devices.
6. RESTART Mobiflight and Arduino.
Now Test the System. Not sure if Mobiflight already combine the new Names.... If not you must do the "Device" Choose in all the Configs once again. ( So you should know what A01 means what device

)
RESULT:
If you are affected by this Bug (I think so) then after Rename your Problem should be gone.
Can you Confirm ???
If Yes ..... Please send me all 4 Files .... The 2 Original Files (mmc, mfmc) and also the 2 reworked that are ok. (pizman@freenet.de) Use "horenh Mobiflight" in Header!!!!
If Possible please tell me what devices in problematic files was broke (Name and Pin)
If NO .... Then you have a other Problem.... I will help you with research. But thanks for doing the test above to support us with taht fact.
Looking forward to your Reply.