Not doubting; your issue is being addressed. If you work with the helpful folks in this peer group (users just like yourself) an answer should eventually surface.
Considering that the behavior you describe has not been seen here in any version, nor been reported, this hints at a local issue.
Please list PC specs: RAM, CPU, GPU, and free space on the drive. If possible, try VP on another machine.
Try this first... go to OPTIONS | EDITING tab and in the Advanced section at the bottom choose NONE(cpu only).
If no change, close Videopad. Go to these folders on the PC and delete all the files that they contain. Reboot, and reinstall Videopad.
"C:\Users\<PC name>\AppData\Roaming\NCH Software\Components"
"C:\Program Files (x86)\NCH Software\Components"
The next step might be to do a thorough uninstall, using this free tool. Delete all registry entries it finds as well. Then install the linked version above.
Report back on what worked (or didn't) for you.