why are my 24 or 25 FPS iPhone 6S Plus videos jerky when I import them into iMovie on my 8th gen iPad?

Hi,

I've been shooting a few videos on my iPhone 6S Plus (128 gig) at 25 frames per second using ProCamera app just to keep file sizes down and avoid light flicker. They play fine on the phone itself or when I import them into iMovie on the phone.

When I try to edit them in iMovie on my 8th Gen iPad however they play very jumpy and jerky. They do play okay however straight from the library.

Is the minimum frame rate for my iPad iMovie 30 fps? I'm in the UK by the way.