Open Cities Skyrim

So, in short and in order.

About the bugs found in OCS.
1) A bug with the door in the Windmill tower (occurs not always, rarely, maybe in one case out of 10 the door works correctly. )
I discovedre and Drengin has replicated it
2) Bug with the disappearance of the NPC. (trigger USSEPBug28829NPCFailsafeDUPLICATE001)
Discovered by Drengin. Untested by me but provided is attached fix plugin

TESTING AND HOW TO REPLICATE
1) TESTING DONE TIME AND TIME AGAIN.
NPCs cannot go through the door in the Windmill tower.
The NPC can disappear under the Lower Gate arch when moving away from the city.
The NPC disappears on the bridge in the docks, moving towards the north.
The NPC disappears, moving from the lighthouse in the direction of the city, passing the pirate ship and a little before reaching the Rock Arch.
Other NPCs may also disappear in these places.
I personally believe its something to do with auto-load-doors sending the NPC to same space or close proximity whether it s a vertical z-axis thing or just being close.

I have made a Door-to Door-teleport in some my own works changing the baseform of the auto-load door.
Door in Windmill Tower to the Docks Door. Years have past and never occured since

TESTING AND HOW TO REPLICATE
2) TESTING DONE BY DRENGIN
I used the player.moveto command, which teleported me to the mercenaries. They ended up in home taverns, where their reference is located. (in two experiments Belrand ended up on the street, apparently he started moving towards me while I was typing the command).

I opened Open Cities Skyrim.esp in CK and looked at what is in these places.
And there is a USSEPBug28829NPCFailsafeDUPLICATE001 trigger that runs the following script

Scriptname USSEP_SolitutdeNPCFailsafeScript extends ObjectReference  
 
Event OnTriggerEnter( ObjectReference akActor )
if( akActor != Game.GetPlayer() )
akActor.MoveToMyEditorLocation()
endif
EndEvent

This trigger seems to be meant to save NPCs that fall down of the city and die. Unfortunately, the trigger box is made too big and NPCs will activate it when moving on roads and streets.
To test, I removed this trigger, and the problem disappeared as expected.