Map Block Doesn't Show Unless Full-size

I recently added a map block to map all of the addresses in a base. It doesn’t show the map in the block, but rather says, “Please make this block bigger or full screen”. When I make the map full-screen, then I see the map, but not until I make it full-screen. How do I get it to show the map with pens in the block without having to make the block full-size each time I want to see it?