hm... i would like to highlight a scenario that this software is in real something like a freeware app or a program for a pc game and the only answer is that is has a program error while several people here perform a brain storming.
in this case you will get no answer- in the case your question is for real i would suggest to contact your technical department instead an anonymous forum which should help you.
when you claim brake energy is not a limiting factor i personally have no idea what is going on.
best regards