Tomas,
I have more strange things going on with my micro.
I still can't adjust rudder limits.
If I spool it up the heli spins cause the tail motor doesn't start up.
And now I lost channel 7 in diagnostic screen if it's bound in DSMX which was working yesterday.
If I bind it in DSM2 I get channel 7 back.
I did a factory reset same result.
Totally frustrated with the micro at this point.

Maybe the problem is in the frame rate. When you will bind it as DSM2 and DSMX the framerate can be different.
You should see it during the binding process. Can you tell me what is your radio?
Also you can check if the Bank Switching is really assigned in the Channels.

These things are very same between all Spirit units so there shouldn't be anything special.

By "lost" channel you mean it is not responding?

I recommend to solve one thing at the same time, so step by step.

_________________
Spirit System developer

Had it bound yesterday with DSMX 11ms with bank assigned to channel 7 and it was responding.
Today it wouldn't respond to bank switching in diagnose tab. So rebound it with DSM2 at 22ms and channel 7 responds. Tried to different DSMX satellites. Using a DX9 copied radio setup from my other heli with Spirit Pro. So bank switching in radio is the same.