Note expression on multiple notes ruins sound

I have recently started to use note expression in Cubase. It`s brilliant for arranging string sections where you can add some “life” to the sounds.
I use expression to draw in some movement in the dynamics of separate notes.

This works fine when i only draw expression on one or two notes, but when i draw expression to several notes the sound becomes almost distorted. It sounds like all the notes are stuttering. It just seems like Cubase can`t handle when expression is used on multiple notes at the same time.

This happens with different VST Instruments, so the problem is not there.

Has anybody experienced anything similar or have any idea might be causing this?