When I attempt to use the full screen preview (the button with the tool tip of "Video Preview on External Monitor (Alt+Shift+4)"), the video does go full screen, but it flashes all-black every half-second, continuously. Is it because this button is only made to preview on an external monitor, not my (one and only) main monitor?

I'm on Vegas 23 302, on an Intel i7-11700b with 16GB of ram, with on-board video. I updated my Intel video drivers hoping it would fix this, all that did is break Vegas completely (but I got it working again thanks to answers in this forum - I had to copy a working vcomp140.dll into the Vegas folder).

Or is there a different button to use when I want to preview full screen on my main monitor?

Thanks.