More Bridge Trouble

So I've made a new tileset that includes a bridge that is meant to be passed over/under. I've matched it to Essential's bridges in every way?terrain tag (15), priority (4), layer (3rd), and passability?yet it's not working the way it should. I am triggering pbBridgeOn and Off as normal, but the problem lies mostly within the passability. Here is the bridge:

The 3 blue tiles above the arch are the "bridge." Much like Essential's bridge, they are not passable at their tops and bottoms.

So when the player walks over the bridge, pbBridge is activated, things work as they should, and life is good. But when the player walks under, pbBridge is inactive, yet they get stuck by the passability of the bridge:
which looks like this:

Shouldn't passability be overridden when pbBridge is off? Can someone please explain why is this happening? Are there certain tiles meant to be placed a layer under the bridge, or is it something to do with the mysterious TT of 13...

You must set this tileset with high value Priority in Tileset (Database).

You mean set the priority of the bridge right? The bridge is already a priority of 4. I'll try making it 5, see if that does anything different.

and you need set Passage -> 4 dir (because you set 2 dir. So, the player can't move)

As I can notice from your image, the bridge tiles do not include the up border of the bridge (the down border is included as i can see). If you done everything correctly, the only problem is that border that you may have set as non passable, while it should be a bridge too.