As of a week ago, Roku no longer provides accurate search results for shows and their channel options. I thought it might be a temporary glitch, but the option seems useless at this point. Honestly, it’s part of why we equipped our home with Roku tvs, and this is a serious disappointment…or a major programming screw up. Y’all need to address this quickly, or you will lose customers.
This might be the result of changes made in Roku operating software version 11.5, which is slowly rolling out.
Settings > System > About will show you what Roku software version you're running.
I don't have 11.5 yet on any of my devices, but Roku's announcement of 11.5 touts "an all-new content discovery experience".