Not seeing Global Block element as option

Hi there!
This is an awesome plugin – can’t wait to start using it in my projects! I’m running into a snag where the Global Block element isn’t an option in Cornerstone once I created the block.

Not sure if it matters, but I’m running Multisite, both Cornerstone and Global Blocks are activated at the site level. I did try it with Network Activate but still no luck. Any help would be super appreciated! ??