Hi.
One issue I've had for quite a while now is that sometimes (especially in complicated projects), the frame rate on some sequence(s) are low. I normally do 60fps videos so that really shows.
I've managed to create a small Project where I can replicate this issue every time. Could you have a look at it?
In this one the issue happens right at the beginning, but usually I have this happening later in the exports. Might be the flip transition causing it?