Why is my player stuttering when I set the velocity in the update function?

My character moves on it’s own which is what it is meant to do. I make it do that by doing this:

rb2D.velocity = new Vector2(0, speed);

rb2D is the rigidbody and well it is not a stutter that is noticeable just a slight stutter. Is there any way I could prevent this? I don’t want to use the addForce(); because it just gets faster over time which is not what I want. I want a constant force without this stuttering. If there isn’t a fix it’s ok because it’s not a major thing but it has annoyed me a bit so that’s why I’m posting here.

Thanks for the help!

Hey! No need for help anymore. I was messing around with the ridigdbody and found out that I needed to change the interpolate to interpolate when it was at none by default.

I would like to know what this does. So if anyone knows anything about that feel free to explain that to me!