The "My Communities" List Does Not Display All Of My Communities. Is This Expected Behavior?

There seems to be a hard numerical limit of how many communities can appear in the "My Communities" menu. For example, any community I'm a member of that's below "star-wars" alphabetically, like "technology," cannot be scrolled down to or searched for.

I have no idea if this is by design to avoid people adding all 5,000 communities and slowing down the menu, or this is a bug. Was wondering if other people are running into this limitation. If it's by design, a few extra slots on the list would be nice to have!