Clips looking weird at the beginning...please, look at the image here.

Hi! This is my first time posting here, the thing is something weird has been happening with my clips lately and I don't even know how to describe it that's why I'm adding a picture. The only thing I've done to this cilp is changing the speed because I want it to be in slow motion, that's all! I've had this issue a couple of time before and the only solution I found was just deleting the beginning of the clip, but I don't want to that every time! Can someone help me, please?

(Also my premiere pro is up to date.)