I tried this a few minutes ago... My Launchpad then apparently stuck in the Other folder. Escape did not help. I could click out of Launchpad through the Dock, but re-launching it would go straight to the "Other" folder.
I finally got out of that folder (returning to the main Launchpad screen) by double-clicking outside of the Other area. I can't get it to do the same thing (locked into Other) now. I don't know what happened, but my Launchpad appears to be responding normally now. I rarely use Launchpad, but I had just done a lot of "trimming" of caches folders on my Mojave system, and it was the first time I tried Launchpad since that bit of maintenance on my Mac.