I have used Vegas since version 3 and never seen this which is happening in 19 and 20. When I switch to 4K or UHD, the video preview window changes to a vertical phone-like aspect ratio with extremely low resolution. I have no idea why this is now happening. This is just a normal project file, no massive amount of plugins, nothing extreme, just default settings after installation. When I turn on secondary display, the image is strangely small also. I never had this happen doing what I am doing on any computer in all the past since version 3.0 .I am using a Windows 10 pro 64 i9, 128 GB RAM, RTX Nvidia 3090. This must be some weird glitch because it is the current version, and the most recent driver for graphics..