Your Gcode looks OK.
From your .xml, you are using Output#1 for your spindle M3 /M5 commands and creating a conflict with the M11P1/M10P1 commands.
Change this to Output#2 in Spindle Setup for both M3 and M4 and also Enable Output#2 (set to an unused output pin) in Output Signals.
Hopefully...
Tweakie.