Problem 1: VP 20 and VP 18 Explorer Pane gets scrambled and unreadable. Fix: ASUS motherboard drivers include Sonic Studio 3 and Sonic Radar 3 that some how interfere with VP 20's Explorer pane displaying properly. I chose to uninstall the 2 Sonic programs. Here are the details for fixing:  https://www.vegascreativesoftware.info/us/forum/project-windows-not-displaying-properly--125441/ 

Problem 2: The Canon R and R5 video files when placed on the timeline cause VP 20 and VP 18 to crash. Fix: Preferences/ File I/O must not be set to Auto or to (NVDEC on Nividia Geoforce RTX 3070 Ti) but instead set to OFF or Intel QSV (if available)

Problem 3: Slow rendering of Canon R5 10bit hevc 4:2:2 video files. Partial fix: Use Magix hevc/avc (nvenc) rendering template and set it to 10 bits per pixel. Although chroma sub sampling can only be set to 4:2:0 and the Canon video is 4:2:2. These settings result in a rendered video file that is hevc and I assume 10 bits per pixel and 4:2:0. I found that the Magix avc/aac mp4 which is permanently set to 8 bits per pixel rendered the same Canon 10 bit hevc file to an AVC mp4 file which may be easier to play back on older computers. This tutorial helped: Rendering is still a lot slower than with Canon 8 bit video files but useable for small projects.
Problem 4: Canon 10bit hevc video files do not Preview smoothly. Fix: From Project Media tab make proxies for editing.