H-bridge PNP transistor overheats
You need 12v on V2 and V4, otherwise you cannot turn off your PNPs, they will be on all the time.

When those switches deliver 0v, the PNP is on and the NPN is off.

When the switch delivers 3.3v, the NPN turns on, but the voltage is not high enough to turn off the PNP. There's still 8v across R1 or R3, which keeps the PNP on, fighting the NPN. You'll measure any voltage between 1v and 11v under those circumstances, depending on which one 'wins'.