Is the material LINKED audio and video or has the audio track been added independently and synchronized?
If the former, a right-click|DELETE (ripple) should affect both A/V tracks equally.
If the latter, select both audio and video clips and right-click|GROUP them. That should prevent the issue.
The difference in this case between the free (trial) and licensed version is irrelevant.
If no joy, please share the project per the "Tips for getting help..." post near the top of this forum. Someone will take a look.