So I have a game I'm working on that is grid based. I noticed if the window is a certain width, then the grids will have vertical lines separating them. Below I attached two images, one with the screen at 905px (with lines) and another with the screen at 906px (without lines). It alternates between lines or no lines every 3 to 4px.
There is an online version located here - Game Link
Any possibly explanations would be greatly appreciated!