I've only noticed this at resolutions higher than 1080p. Setting the resolution higher than this, whether it's done in-game or via the launcher, the buttons in the lower portions of the screen, such as "Join Game", will not be clickable. Instead, you'll see the regular Windows cursor.
Apparently there's an issue where the game doesn't set the right resolution. It *looks* as if the resolution is 1440p/4K even though it's not. Minimize the game and maximize it, and the problem goes away. Note that it might take a bit of work to get it to minimize, in my experience the game stays on top even after attempting to Alt Tab, you might need to do Ctrl + Alt + Delete a number of times before the game wants to minimize. Bring it back to the front and it should work fine!
Ive had issues with just changing the resolution in general. Once I click apply, the game screen is still visible but flickers insanely fast, and the game is no longer playable. I have to ctrl.alt.del to bring up task manager (for some reason shift+esc doesn't work when this game is launched???) and half my screen will be blocked with a black box. Still haven't found a solution :(