Without seeing a screenshot, I can't say much. But GK2 did display the videos in a way that might seem wrong.
Attached is a screenshot from my computer. The way I've always remembered the game looking.
(Sorry about the size, but I was a bit worried about the lines not being visible if it were smaller)

The technical term is interlacing.
There is a way I've heard about removing it, but I've never tried it.
https://gkpatches.vogons.org/
(If you're using Windows, I would presume the standard caution of checking out every file you download would apply.)

For any other troubles, I doubt if I could help much.

Though perhaps if others saw what the tearing looked like, it might give them an idea how to help.

Oh no, that's not what I mean.. I am using the de-interlace patch btw, I never liked those scanlines.

Anyway, the problem I have is tearing.. like in this screenshot -

However, I downloaded Gulikoza's custom build and that seems to have fixed it.. I wonder if it's related to the VGA_PARTS 4 setting in Dosbox.. read something about that but I have no idea.

But it seems much better now with this custom build by Gulikoza 😀