OK. Let’s see how this goes. From looking at your molding, it appears you are not running Follow Me correctly.
After moving the molding up above the model, it’s easy to see there are gaps in your path. Some edges are still part of the wall.
And some edges are in the group but not connected properly.
I started over by copying the profile out. Do that by double clicking with Select on the end of the molding. This is done with the group opened into edit mode. Then hit Ctrl+C to copy it. Click outside the group to close it and then delete it. After it’s gone, hit Edit>Paste in place.
I left the molding above the walls so it won’t join with the walls. See the little white thing near the cursor. Then select the top edges of the walls. Hold Ctrl or Shift while selecting them. Make sure you select all of the edges around the room.
Get Follow Me and click on the molding profile. You may get that not on path message but you can ignore it.
With Select, triple click on the molding and then right click on it and choose Reverse faces so the white front faces are facing out. Then, while it is all selected, right click on it and choose Create Group (or Create Component). Finally, move the molding down into the room.
While you are doing this stuff, triple click on the walls with Select, the right click and choose Reverse Faces. Then make a group or component of the walls so that stuff you add later doesn’t stick to them