iPad 10 iMovie and 4K

Hi,

i just bought the new iPad 10 and wanted to make a movie with the iMovie app. If i only choose pics im able to export the video in 4K but if i do this with my 4K Videos from the Photos app iMovie only gives me the

option to export in 720p. Am i doing something wrong alhthough there is no option in iMovie for importing videos only in 4K. Maybe iPad 10 is not the best tool for 4K? Im on the newest software on both

iMovie and iPad OS. The Apple Care hotline couldn‘t help me out because the Apple advisor on the Phone (Austria) told me he never heard about the App iMovie :(

I hope someone will help me here.

Thx