Fullscreen Alt-Tab bug

TL;DR If I fullscreen and alt-tab the game will go back in to windowed when I come back to it and in the settings it still says "Fullscreen: On".

Hi, so this has been a problem I've had for a very long time now, and I guess lately I've gotten sick of it enough to do something about it. I'm your average gamer, I play a large variety of games on Steam and out of Steam, and each game I play I prefer to have fullscreen on. In Minecraft, unfortunately, having fullscreen on never really lasts for me, because every time I alt-tab to switch to a new window and go back to Minecraft, it's back in windowed mode. I then have to go back in to the settings, turn fullscreen off and back on again to get it back to fullscreen. I always end up just maximizing the screen because that's basically my only option. Thank you for your time and consideration, have a nice day