The issue could be related to what I discovered yesterday. When I click "View all" next to "Featured [media type] templates" across all categories, it draws a blank. See screen recording.
We're sorry to hear about this. Can you let us know what you're searching for? What is the make and model of the device you're using? Did you try restarting or re-installing the device to see if that helps? You may also try switching the internet connection to see if that works.