612 F1 Transmission Issue

I have been experiencing a strange transmission issue with the F1 transmission on a 2008 612 OTO. Shifts and transmission shifting are completely fine when driving. When the car is hot and I come back from a reasonable long drive (an hour or more) and I park it, the transmission in shifting from drive to reverse and back will freeze, the engine will rev very high uncontrollably without touching the accelerator, and smoke like clutch burning smell occurs front and rear. The clutch is not worn and the accumulator was just changed but this did not fix theproblem. Does anyone have thoughts orexperience with this problem? Thanks.