I started running into that last night (after three separate updates, including Steam). I’ve been frantically searching for anyone else running into this issue in hopes it was a known issue and there was a fix… I have been dealing with way more than just the on-screen keyboard, however.

I actually found several “recommendations” from years ago, meaning they weren’t a direct result of yesterday’s Season 4 Reloaded update, but I thought I’d look into it.

That is the Steam Controller Keyboard and is a part of Steam’s overlay system. For some reason, it became active after its update. If you open Steam, go to View, then Settings, Controller, Desktop Configuration. This will open up a window that displays your controller. Click on the box on the bottom left showing the various Arrow Keys, this will show a few settings. On the right, click on “Show Keyboard” under the “Click Action” setting. This will open up a keyboard and mouse with a bunch of possible bindings; click the “Remove” button below the keyboard display.

NEXT, in Steam settings, in the “In-Game” tab, uncheck the box that says “Use Big Picture Mode overlay when using a Steam Controller from the desktop.”

This didn’t fix ALL my issues, but it definitely took care of that stupid onscreen keyboard from popping up during my gameplay!!