Please upload videos and pictures directly to the forum using the icon between the second paperclip and the smily face.
The answer is that you are likely using VEGAS Pro 21 build 300 or newer and it has some bugs with the decoder and certain media formats? If you are not using 315 try it. If you are, is the media HEVC or AVC?
Would it be possible to upload a short sample of footage for testing purposes using Dropbox, Google Drive, etc? Anything from the same camera would be fine.
For a workaround you could try legacy AVC or experimental HEVC decoder in options/preferences/ file io. You could also attempt to convert the footage to a format VEGAS works better with- I make constant framerate h264 using Shutter Encoder (free).
Alt+F9 will start video recording the screen without opening the Geforce App, Alt+F9 also stops recording 👍
Alt+F1 will take a screen capture pic.
Or Windows key+Shift+S will open windows screen capture, the screen will go dark & options will appear at the top of the screen, the captured pic will be in Notifications bottom right of your screen.
If you do open the Geforce App click the cog wheel to open Settings, top right are system specs, share a picture like this,
-------------------------
how do I check the media for HEVC or AVC
In the link @RogerS supplied is mentioned MediaInfo, this is how it goes -
The App is called MediaInfo, download it, it's free & a fast download with no added adverts or any of that rubbish. https://mediaarea.net/en/MediaInfo. After downloading, right click on the media file in your Windows folder, open MediaInfo, choose Text from the options at the top, screen capture that page or Copy & paste the information in a new comment on here using the arrow button next to the smiley at the top of a new comment 👍