I think something happened with the attached BT. Could you please send it to info_at_nodecanvas.com?
I can’t really replicate a case where OnUpdate is not removed and thus is called twice.
If OnUpdate is called then elapsed time will be greater than 0 and thus the method will be removed.
I suspect it could be a Set Mecanim Float bug rather than ActionTask one although I can’t reproduce it, but it would be great to send me your behaviour if possible so to make sure.