The easy way is to use (the default) solids. Doors & walls must be solid. Regenerate the map. Do this under 1 'trigger once while true.
Use 'Regenerate region around object (the door) when its frame changed (close AND open). And ofcourse, after you changed its 'solid state'. It will reconize the changed 'solid state' and adjust the obastacles arround the door.
Be aware that the obstacle map is ready the next tick (NOT this tick). So, the 'find path' you can do at the start of the event sheet.
The 'on path found' you can set wherever you want. But, i dont see it in the pict. So i have no idea how often you force it to find a new path. Cant be done to often, because then all it does is search, and before a path is found, it will be searching again.
The way you do it, all obstacles all over again, it can take quite some time to generate the obstacle map. And you probaly found a path before the obstacle map is ready.
Also, there is ONLY ONE obstacle map. So setting new obstacles for one pathfinding object will change the obstacle map for all. So, dont use a 'for each' to set obstacles for all pathfinding objects.
So what do you do wrong? I can guess, but i have no idea. I dont see the layout. Is the door to small compared to cellsize and cellborder? Did you forced it to look for a path before the obstacle map was ready ? Do you force it to find a path to often ? Are the collision polygones weird ? But i suppose, with those tips you can solve it.
If you want to be sure, start a timer on the moment you regenerate the obstacle map (like 0.2 secondes). And when the timers goes off, let it find a path.
Hope this 'rambling in the dark' helps you some.