Pronterface gcode 28 and 29 not recognized

I use Pronterface and repetierhost to print.
With pronterface the gcode 28 (homing) and g29 (leveling) no longer work.
The carriage remains stationary and after a moment of at least 1 minute it begins to print as if the temperature had been reached.
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.

Manually check that no endstop is being triggered and send the machine a M119
It should tell you all endstops are open

now choose an endstop and manually trigger it (for eg hold down switch with a finger) now send another M119
The printer should now tell you that endstop is triggered.

Check all endstops

Thank you for answering.
Sorry G28 and G29 work well. It is the heating that does not work. I am creating a new post.