When importing Topaz Video AI generated MP4 either H264 (AVC) or H265 (HEVC) Vegas pro 22 (B250) reads the frame rate as 12,800.00 and as such when added to timeline only adds the first few seconds. see attached screengrabs
Also a template of 240fps is somehow loaded, complete mess preventing editing Topaz VAI V 6.2.2 2025 generated files.
Use Media Info program. Topaz generates such rubbish files.
1. Run VirtualDub in copy mode – it should help. 2. Use ProRes in Topaz – but it seems to have bugs too. 3. It's generally best to export to FFV1 in Topaz and recompress to ProRes/H26x in ffmpeg.