The GameDev Lounge 00000011

[Bombshell93]

I didn't think I could help at all before but did she try reversing gravity and placing the player under the block to see whether it was the box was too big or just offset? preferably do this with a sprite which takes up the whole hitbox, for accuracies sake, maybe test left and right just in case too.
if the hit box is too big you can now narrow down efforts into which hit box is wrong, possibly via another very basic "nothing can possibly go wrong" box, if both are still too big it may be a quirk of unity's physics engine, if results are inconsistent across multiple tries it could be a problem occurring as result of a collision, perhaps manually handling momentum and such in a collision related event (quite common when trying to get a platformer not to feel slippy), if one is too big you have your target of investigation, perhaps manually setting the bounds would fix. If results inconclusive trying out many collision primitives could help narrow down whether or not its a quirk of unity or something to try and fix.
if the box is offset investigate the object trees (draw objects, meshes, rigid bodies, etc.) for any incorrect transforms.
If all else fails, a thought comes to mind regarding the half-pixel offset on texture sampling which might result in an unforeseen shift in the graphics, past that nothing comes to mind at the moment, but if this is still of use I can update if I get any more thought's on the matter