Can't get back in after I Alt-Tab?

The new fucking update broke the game to an unbreakable extent. I don’t know why every update makes this game shittier and shittier.

“broke the game to an unbreakable extent.”
What does that even mean? If you want some help then give us some useful information, QQ’ing about problems in a game that’s early alpha isn’t going to make it work for you.
Personally, I haven’t had any problems alt-tabbing, before or after the most recent update.
One thing that may make it better is to not use the server browser. Get the IP for your preferred server and use the net.connect command in the F1 console to connect without pressing the “play game” button on the main menu. This improved my FPS quite a bit as well as opening the ESC menu, it may help with your alt-tabbing as well.