This glitch has been around since 0.15.0, and it sill hasn't been fixed. I guess no-one over at Mojang is left handed, haha! ¯_(ツ)_/¯

To achieve this glitch, all you need to do is enable lefty mode in the settings. Next, go to any world and you will see the open inventory button to the left like it should be. However, when it is opened the button shifts over to the right as if the player had lefty mode turned off. However, when you close the inventory the button goes back to the left where it should be when it's closed. This bug is not major, but it is kind of annoying.

Device: Samsung Galaxy S7 (SM-G930A)