Hello, if the issue happens with other programs or applications then is likely that the issue could be either your soundcard hardware or a driver issue. You may want to update your computer's sound driver and check if there is any particular steps you take before the issue starts or if this would be random. Also. the only way to accomplish what you want on Mixpad would be to but and replace the part of the recording since Mixpad does not have an overlay feature as what you are describing.