Just something quick to try while Overloaded is looking at your code.
It may be that a G4 command (Dwell) has been included after the plunge. The timing for this is denoted by the P comand, which in you case might be set at say 5. This can be 5 milliseconds, which you wouldn't notice, or 5 seconds, which you would.
The time delay multiplier is et in Config/General Config/fourth column, 2 item. If it is not ticked (seconds) then tick it (milliseconds) and this may get rid of your problem.
The only other thing is - will your supplier come and fit me a new CPU
