How to get rid of weird artifacts

I’ve made a procedurally generated grid of tiled sprites with platformer behavior.

This is how it should look like:

But sometimes when you move it flickers to this image:

You can see some weird lines below the individual tiled sprites.

I’m not applying any form of scaling on those sprites, and I’ve created them using the “Create an object from it’s name” event.

Does someone know how to get rid of these visual glitches, since they are quite bothering to me.
I suspect is has something to do with the fact that these are individual tiled sprites rather than a tilemap, but that is necessary for it to be procedurally generated (I believe).

What is the default size of the tiled sprites?

The default size is 64x64 pixels.