Hey o/
well, first of all, take a look at your layers tab to make sure everything is in the right order
and also check each of your sprites or any other objects to see if they're on the right layer
(upper layers = objects displayed on top)
if that doesn't solve the case, check if the Z elevation of each object is right
Z elevation is basically a simpler way to manage which object displays on top of
Try sending your tiles to the back, or your sprites to the top
that said, i'm pretty sure i'll be all done