I place doors in a way that when they are closed they are technically open, so zombies cant break them, but if you place a pressure plate (any kind) it doesn't work, when you walk over the pressure plate nothing happens, and when you step off it opens.

I posted a video of it on reddit 

https://www.reddit.com/r/Minecraft/comments/c2v1u6/pressure_plates_not_working_properly_on_open_doors/