Lose audio sync when exporting

[coted]

VideoPad Professional v. 6.10 on Windows 10

I'm aware that there are a number of threads on this subject, most dating back to the 2014-15 time frame.  After reading a number of them, I don't see a definitive solution. 

My source is an mp4 file recorded by a colleague with following properties:

Video:  1280x720 pixels, data rate = 9664kbps, total bitrate = 9894kbps, frame rate = 30fps

Audio: 229 kbps, 2 channel stereo, audio sample rate = 48kHz

The file plays fine in its original state.  I have cut 5 clips out of it and spliced them together into a new sequence.  This plays correctly in the VP editor.  After exporting this sequence to a 720 P mp4 file, the audio gradually lags further and further behind the video.  The total length of the new video is around 6:30.  

Any new information on this issue will be much appreciated.

[borate]

As there are but five clips, please share them, and someone will check it out.  Here's how...

1.  Save your project.  Then, with it on the timeline, click the FILE menu. SAVE PORTABLE PROJECT AS to any convenient folder.

2.  Open the folder that contains the saved files and ZIP them all.

3.  Upload the zip file to DropBox, Google Drive, MS OneDrive or the like.  It's free.

4.  Make the uploaded file public (share it) and copy the shared link.

5.  Paste the link into this forum.