In all the 1.16 beta versions I've encountered this issue where pressure plates placed on the opposite side of a door don't trigger after the door is opened manually and the player walks over the pressure plate. The door will remain open until the pressure plate has been triggered again or until it is closed manually. The pressure plates don't seem to have an issue with opening doors as far as I can tell.
The video below was recorded in 1.16.0.53, but i've experienced the bug in the more recent versions as well
Thank you for your report!
We're actually already tracking this issue in MCPE-47509, so I've requested this be resolved and linked as a duplicate.
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