Same experience here on v505220835 after update and first use. It displayed a search top menu bar with TV Shows TV Movies Shows etc but then crashed to OS (Nvidia Shield TV) before I could search for anything,
But when I went back in after the crash and tried again it worked OK and I was able to use the search. I presume by design so as not to have too many results, it doesn't display anything until you have entered at least 3 characters, but it seems to be working fine on my test examples. It found TV Shows, TV Movies and Shows for my test search strings.
But, then after going back to Live TV and back into Search, it locked and crashed again.
Must be getting close and the basics of the search did work well before it crashed.
Diagnostics submitted ae81f051-21d1-4986-9745-8b34f6f348fe