...draw gridlines at runtime for a consistent look?

Hi,

I am trying to draw gridlines at runtime for the player to better understand the map layout. I have an event and action that draws horizontal and vertical grid lines based on a tiled background. The problem I am having is that the lines are not displaying with a consistent look nor do they all show up sometimes. Is there a different technique and/or object I need to look into? I didn't see anything in the tilemap object's actions to show the gridlines so I invented my own.

Here is a video showing the problem.

youtube.com/watch

Here are some screenshots

Thanks!

Thanks. I still haven't got it to work right. Sometimes the gridlines draw perfectly horizontally and then are off vertically by 2 (missing) and vice versa. It has to be a drawing issue. I put in a wait 1 second for each run of the loop but that didn't help. I may need to just make a new object that already has the grids made before run time.

Also, I noticed it changes based on whether my preview window is fully expanded versus a different size.

I have ran this on two different computers.