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.
