LinuxCNC stalls on manual toolchange routine

Hi there,
I'm currently facing some problems with my LinuxCNC setup. I have remapped the M6 command to run my macro for measuring my tool length. However, it's only working the first time the macro (messen.ngc) is called. This means:

• The machine gets switched on and homed
• The first tool is inserted (for example, T1) and measured with the macro
• The zero point of the workpiece is set
• Another tool is called via T2 M6 (MDI)
• The machine moves to the manual tool change position and waits for the tool change
• Upon confirmation of the tool change, the machine starts moving (to the position of the tool length sensor) and then immediately stops without fault.

I really don't know what to do anymore. LinuxCNC isn't throwing any exceptions on the Gmoccapy screen or in the terminal. It would be really nice if someone could help me out. I'm running the following setup:

• HP ProDesk 600 G1
• i3 4160
• 8GB RAM
• Mesa 7i95

Thank you very much and best regards,
Raksop

I added some debug lines to the code and did the same procedure.
First tool call works and the machine stalls on the second tool call after the tool change is confirmed.
On the screenshoot u can see that the machine called the toolchange macro.