So i had this problem with the asphalt curbs and now these pier objects on my pool. Im pretty sure this bug is universal for all flat objects in the game. (rivers also do this when they meet)

Basically if you duplicate flat objects by CTRL moving them to make a flat area , they will flicker in the areas where the two objects overlap. However this bug can be stopped by SLIGHTLY moving the object out of alignment on the Y axis.

Video attached to show bug and how I fix.

Would be nice if we could fix this bug so we can have perfectly flat and matching parts that dont flicker.