The keyboard sidebar is called one-handed mode
It turns out the Android keyboard has something called one-handed mode. Normally, you enable or disable it from the menu that looks like three dots, in between the gear and the microphone. So it’s easy to get rid of the mystery Android keyboard sidebar once you know what it’s called. Tap the three dots, find one-handed mode in the resulting menu, and tap it to deselect it. Of course I looked lots of other places first, but I eventually found it. I’ll share it with you so maybe you don’t have to look as many places.
I was afraid it was some non-optional system update. So I was glad to find the setting. Maybe this sounds curmudgeonly, but there’s not enough room on that tiny screen for a keyboard and a sidebar with a bunch of functions I’ll never use. And shifting the keys one position to the left or right (it’s configurable!) messed with my muscle memory.
I don’t know what problem one-handed mode solves, and how shrinking keys a good 10 percent makes it easier to type with one hand. But I’m not sure it matters. 30 seconds later, I’ve got my keyboard back to how I’m used to.
How to accidentally enable one handed mode
As best I can tell, I accidentally enabled this keyboard sidebar when I held down the enter key for too long. Sometimes when I’m trying to hold down backspace, I accidentally hold down enter, especially if my hands are a bit sweaty. And to turn off one-handed mode, it takes more than just holding down enter again. But at least I can share how to fix it.
It wasn’t long after that my phone hid my apps from me. But here’s how I found those.