It's been a sporadic issue across multiple steamOS versions for a long, long time. At one point they said they fixed it, but I have the bug on the current version.

I'm sure if you go through the process of factory resetting the device or re-loading the OS and blowing away your settings it can be fixed, but I look at that as way too much work.

This thread has someone with a very verbose set of instructions of how to fix it via command line https://steamcommunity.com/app/1675200/discussions/1/597404077749474647/