If I want to import 60 fps videos into the Quik app, it freezes. With 3840x2160 resolution, the Quik doesn't work on Galaxy Note9. I wish you could improve it. :(
Have you tried working on other resolutions?
Are these files taken with your phone camera or from a GoPro?
For reference, you may also check: Quik for mobile Crashes
Yes, it works in other resolutions. But 60 fps is the best, and I record with this resolution many videos. Please fix it!