Urgent ILS Landing Problem

Posted this a few weeks back but stillo have the same problem.

A few times whilst landing the B737 (ILS) the plane turns to rwy heading and then the AP turns off the ALT Hold then instead of the plane making its decent down toward the runway the nose lift to a near stall and it starts climbing up at a very fast rate beyond FL10 and makes no attempt to descend.

I have landed the 737 hundreds of times on FSX and it has only done it about 5 time.

Is this my fault or a FSX issue, I'm 99% sure all settings are correct my end.

I'm hitting the APP button when I get the final atc approach message.

I'm pulling my hair out here

Thanks