Items 'unreachable' even though path available

Dupes have a limitation how much they can plan pathing underwater by themselves. When they are already underwater they are in emergency mode and they can go any distance.

This is to prevent them from going deep underwater where they can suffocate themselves.

You can check their available path by selecting a dupe and pressing show navigation button.

Have checked path. No access to area. Path not that long or far from oxygen.

Only when I use 'move there' command does it become 'reachable'.

I think it is bug not my gameplay.

Other areas affected.

if you send them underwater they change to emergency mode and pathing limitation is unlocked until they come out from water.

So its possible to build deep underwater under supervision if you have the material in the same body of water too. Because if they come out from the water for the material they cant path back to the construction place.

Maybe red alert also unlock pathing, im not sure. (need testing)

I've had this happen, too - dupes can't 'see' a pump at the bottom of a water-tank from outside to finish it hooking it up.  Quite frustrating.

And then there's THESE idiots.  If I manually walk them to the other side of the airlock and down the hall to right next to the ladder, they'll usually leave on their own, but if I don't, they'll stand in there idly.

(The hallway on the other side of the door IS partially under water.)

Also, I tried building another pump at the bottom of the water in the second pic, but I keep getting 'unreachable build' on the very last segment of the power wire.  Quite, quite aggravating.

I don't remember having any of these problems prior to the Ranching Updated - did something change in the pathfinding?