What version of Videopad is being used?
Open the Windows Volume mixer by right-clicking on the speaker icon at the bottom-right of the window...
This is Windows 11.
Confirm that Videopad's slider is at its maximum. If that's not the problem, please test install this release.
For licensed users upgrades are free for up to six months from purchase date. After that, VP will continue to fully function but a fee is required in order to register the newest. Retain your old install file and registration info. If there's an issue, you can always revert.
Come back here with your results.