There seems to be some kind of time-based bug at the moment.
If you load the page, wait (say) 10s, and then do your search it seems to work.
If you load the page and immediately search, it doesn't seem to work some of the time. For me, it works sometimes and not others. If I wait and then do the search it seems to work always.
I was doing a screen sharing sessing with a product manager at Meraki which using the search function and they saw it not working some of the time for me. So you can rest assured someone is looking at this.