Why can't I voice search Smarttube with Amazon Firestick anymore?

I used to be able to use the Firestick voice search to find YouTube videos on Smarttube(Next) by asking search question and saying “in YouTube” at the end. The Firestick would then open Smarttube and show the search results. Now when I do that, the Firestick goes to app store prompting me to install YouTube. I even updated the Smarttube app. but still no. I’m open to any innovative solution to this recent new aggravation from Amazon trying to cut us off at the knees.