In version 1.15.2 I could place a door, open it, then use two setblock commands (/setblock ~ ~ ~ oak_door[open=flase] replace); one for the top half and one for the lower half and it would closed said door. This no longer works in 1.16.1. It's just destroys the door entirely. This is a similar issue that happens with chests, where you have to use another command to set the block to air first then set another door/chest, which is both tedious and causes you to add extra command blocks.