Patch dropdown selector in editor doesn't always contain all patches

[hhyyrylainen]

I started a freebuild game, played a few generations, saved and loaded in the editor, and then played a bit more. Then I noticed an event in a patch that seemingly didn't exist. I was able to select it from the map but it is totally missing from the selector for some reason:

This might be freebuild specific, but in case it isn't I'm putting it into high priority issues.