After creating a menu, menu transform block does not show up

Problem/Motivation

When creating a new menu, the transform block for it does not show up when you want to place a transform block for it.
The fix is to clear the cache.

Steps to reproduce

1. Create a menu
2. Go to /admin/structure/block/transform
3. Click "Place Block" on any region
4. New block for said menu is not there
5. Clear the cache
6. Try again