Video freeze when tempo track change


I need your help.
I am scoring a film in .mov format inside cubase. I have 10 midi tracks and need to change music tempo via tempo track in some part of the movie to slow down the music.
When movie reach tempo changes, the image is freezing or flicking at each change. Same behavior if I lock the video and video sound or not.
I have try with .mp4 format and it is the same.

Any help is welcome.

I am using Cubase 10.5.12, Windows 10 i7-7700 32GB, Radeon RX 560

Many thanks

Hi and welcome,

Does the video try to slow down to follow the tempo change?

Hi Martin,

No, it just freezes at the tempo jump or if I use ramp during all the ramp time then it works again fine after tempo change.

Thanks for your help