I've set up a server with 1.15.2 vanilla and everything is in default settings except I'm made as an operator and mobGriefing is false. I've installed an OS fresh using Debian KDE latest version (4.19.0-9-amd64) nothing else added to it and no VPN is being used.

I downloaded it from here https://www.minecraft.net/en-us/download/server/ and installed it on the dedicated server on Linux

openjdk version "11.0.7" 2020-04-14
openJDK Runtime Environment (build 11.0.7+10-post-Debian-3deb10u1)
openJDK 64-Bit Server VM (build 11.0.7+10-post-Debian-3deb10u1, mixed mode, sharing)

When I play (locally) it doesn't have an issue, but when someone comes into my server the connection is fine and working great but when the functions like right click to open the door in the game don't work properly it acts like two doors and he can't get through it or try to go to sleep in bed it wont let him go to sleep. I watched his stream and from my screen it don't look like he is doing anything except moving his arm when he uses the right click function but on his screen it looks like the door is in two functional piece like the upper half of the door would open or vice versa the bottom half of the door closes but when he tries to open the bottom half of the door the top half closes and he can't get through. Though I can get through without this problem I'm baffled by it couldn't find a fix for this through a search engine. Almost all the versions are older and not current to 1.15.2 and have different experience with function issues.