White Pixels between Gridtiles

Godot Version

4.2.1

Question

Hey Guys, i started working on my first Project containing Gridtiles too achieve an oldschool Pixellated art style, now i have one Problem. Between the Gridtiles there are single white Pixel lines / Clusters. Super distracting. How can i get rid of them ?
sorry if this problem is way too easy, its my first problem.
ty.

Edit: Theres a Picture of the Problem.