Disable split screen?

You can't turn it off, which seems really stupid when you're given an option for lan play and are both playing on different consoles,maybe you don't need or want to see what the other person is doing in their view either or you don;t have a mahoosive screen just for gaming.

However, this is like the lego games 2 play split screen, it's not a fix, but it's something you might be able to use.

I play it takes 2 and lego games on steam usually with my daughter, Most graphics cards allow you to plug in two monitors (or even if you haven't got one plugged in and enable extended desktop you can move the mouse itno som phanom zone off screen)

My point however, in steam (And it should work with other split screen games) there is a display config you can download called "softh", you simply pop it into your exe folder, edit the text to set the screen size of your main montior and your tv / spare monitor etc, it will then automatically resize both left and right (Or up and down) to fit, so essentially both of your views are playing in seperate monitors like expanded desktop but in different resolutions on each, you can specify which is left and right to show the view you want in the monitor you want.

Admittedly, you need a decent graphics card though this works flawlessly with very old ones I have tested on good resolutions, and also if you only are using one monitor you're rendering things that can't be seen in the other or into nothing (But you can set that to a tiny resolution so it doesn't impact your play much)

Hope that helps

https://www.garethjmsaunders.co.uk/2014/04/26/playing-lego-games-across-two-monitors-with-softth/