heating commands do not respond

I use Pronterface and repetierhost to print.
In pronterface (but not in repetierhost) after gcode 28 (homing) and g29 (leveling) the heating commands do nothing.
The carriage remains motionless waits approximately 1 minute and acts as if the heating commands have been completed and prints.
There may be a track because for a test I launched the code M320 which allows cold printing.
But since and after having left and relaunched pronterface several times nothing helps.
It looks like the M320 command is still active (but not in repetierhost which works correctly).
attached my startgcode

The only way a home can interfere with heating up is if you have a broken wire that moving the axis pulls apart.


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With repetierhost it works. But with pronterface it doesn't work.
This comes from pronterface which misinterprets the startgcode (attached).