So homing using the buttons in the PD do the same as putting the G28 manually. That works.
I updated the firmware of the PD but this didn't do the trick.
Really seems like it doesn't like it when the G28 is in the start Gcode.
G21 ;metric values
G90 ;absolute positioning
M83 ;set extruder to relative mode
M107 ;start with the fan off
G28 ;move X/Y to min endstops
;G29 S1 ;Mesh bed leveling
G0 X120 Y8 Z2 F4000
G1 Y-5 F800 ;move out of print volume
G92 E0
G1 F2000 E-1
G92 E0 ;zero the extruded length for first drop
G1 F200 E25 ;Extrude 3mm
G92 E0 ; zero the extruded lengh
G0 X90 F4000
G1 Z0.2 ; Move Z axis to start line
G91 ;relative positioning
G1 X-60 E9 F500 ; start purge line
G1 Y5 E1.56 F500
G1 X25 E8 F500 ; finish purge line
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
As soon as I comment out the G28 in the start gcode and do the homing before everything is fine.
So as I was able to do my print this case is solved for me. However it feels like a bug. If you need any furhter assistance just let me know.
Cheers,
Markus