MOV format is buggy

Hi!
New to After Effect.
I found the MOV format material, threw it into AE 2019, and on each video material, a lag appears at the end or in the middle, and the video starts anew at the last second or in the middle of the video.
I have already tried to change the video format, installed third-party programs to change the encoder, downloaded the latest version of QuickTime, rummaged in the settings, nothing helps:((
Help me, please, I'm tired...