oh wait. you are telling the machine to do balance cutting (G68) but the two process paths you want to cut are completely separate so it is not a balance cutting operation. try removing the G68 and let both programs run by themselves.
you may need to add a waiting code at the start of the cycle so they are both positioned at the start diameter and ready to go and another wait code at the end of the cycle and leave the tool at the same X position until the other head has completed then move both turrets away together.
program 1 program 2
G0 X4.3 Z-5.5 G0 X4.3 Z-18.9
G71 P10 Q11 etc G71 P10 Q11 etc
G0 X300. Z300. G0 X300. Z300.