If this happens all you have to do is press the microphone on your remote (it’s on the remote and the remote app) after pressing the microphone say whatever your looking for. You will then see “thinking” on your tv screen and the thing you searched will be up there as well as other things you may be interested in. Maybe I wasn’t detailed enough on the other reply hopefully this helps everyone
I posted this problem about a month ago, and I wanted to report how we fixed it. System update did not fix it (the problem started right after a system update). Also, as I said, my remote does not support voice search.
But I did go into settings and poke around, and I ultimately chose a new visual interface for the home screen. This seems to have rebooted my left-side menu options, and search came back. I know this is not a very detailed or satisfying explanation. The analogy I'd offer is to installing and uninstalling an app on your phone, or maybe hiding and then re-showing the toolbar in Microsoft Word. I'm convinced I "fixed" this just by getting the television to reorganize what it shows on the home screen, and nudging it back towards the default. Maybe another analogy (which will show how old I am), is banging the back of the tv when the channel was not coming in clearly.