Hybrid converted video loses 5 seconds compared to original..?

[IanTopaz]

    I am deinterlacing a NTSC 720x480 DV AVI 29.97fps video with its 4:3 appropriate aspect ratio PAR into a 640x480 square pixel Bob 59.94fps .MKV.  Later I intend to upscale in Topaz Starlight Mini.

It seems to have done an OK job visually, but the resulting video is 5 seconds shorter than the original. 
The 5 seconds seems to have been cut from the first 20 seconds of the video (not a gradual loss of time). The 1st 20 seconds of the original video is a kind of lead in black video. The scene first fades in at 0:21 in the original, but in the converted video, it fades in at 0:16. So obviously the 5 sceonds is somehow cut from the first part of the AVI video. 

The original has no audio track, nor subtitle track. I've tried a few options in Hybrid. The Config > Input > Ffmpeg vsync handling: passthrough, cfr, vfr, those 3 produce a video which is 13:56 seconds long when it should be 14:01.  I also tried 'drop' which didn't work.

Any ideas how to fix this 5 second drop ?

I am using Hybrid latest version, just downloaded it yesterday.
2025.27.07.1