Timming belt problem

Hi everyone, i bought a freelander 1,8 2001 model and the car has no sufficient power after a long search i found out that the timming belt had jumped 2 teeth. i fixed it once after 5 km the same problem so i decided to replace the timming belt but again the same problem, i checked also the camshaft gear and it was ok no sings of sliding. Does anyone knows why the timming belt always jump 2 teeth???? thanks for your time.

Difficult to say without looking at the vehicle, but it's possible that some valves have already been damaged, which are contacting a piston, and making the belt jump.

But the compression of all cylinders is ok.... today I tried to set again the timing belt after a 5 km the same problems of power but this time the belt was in the appropriate position!