Why is Tubi no longer available on Roku?

I recently got a 32" Roku TV to replace one that got broken, and for some reason Tubi isn't available on it. I almost was to return it because of this. It is not available in any of the streaming channels - I've looked. It simply ISN'T THERE. It was on my old 32" Roku TV. The one I JUST REPLACED. I didn't move to another location and Tubi *is* on the Samsung smart TV in my bedroom. Tubi is one of the main reasons I liked my Roku TV. What gives? It's an ONN 32" 720p Roku.