Where is your probe command?
I think it should be something like this:
G91 G38.2 Z -50 F300; G92 Z 19.1; G0 Z 5
or double probing:
G91 G38.2 Z-50 F300;G90 G10 L20 P1 Z19.1;G0 Z10;G91 G38.2 Z-50 F100;G90 G10 L20 P1 Z19.1;G0 Z10
Take this with "grain of salt" have not tested it, yet.