Need help with tool change and bCNC

Hey folks,
i have a problem with tool change in bCNC. Here is me workflow:

I generate gcode with TX M6. bCNC detects the command an starts the change tool routine.
In bCNC the height of my tester is set to 14mm, bCNC makes the test and starts the program.
This works fine on start.

But on next tool change, bCNC does all the same as in the first tool change, but then
the height is not correct. Sometime it is ramming into the material and sometimes it moves above
the material. So bCNC isn’t using the probed height.

So maybe there is something wrong in my workflow?

Hope someone can help me with this.