Deleted and tombstombed system projections

I was experimenting and tried to delete and tombstone $ce-items to see if it would delete all streams with that category. So now the stream browser says $ce-items was deleted, yet the streams themselves are still available. I made sure that I had MEM DB enabled and yet on restart, $ce-items is still deleted. Is this expected behavior? Is there anyway to get it back without reinstalling?

After replacing with a fresh installation, I am always receiving “No events for stream: $ce-items” in the stream browser when searching for “$ce-items”. The $by_category projection is enabled and it even shows it processed all 20 items (10 of my new test ‘items’ streams with 2 events each). Everything is default with the exception of running mem-db. My test streams are there and browsable, so am I doing something wrong?

edit: I wiped out my EventStore folder and replaced it and cleared all site data from my browser all once again. No difference. I just tried more test events using a different category name and it works. But still the ‘items’ category is empty. Why would the behavior with the ‘items’ category persist even after replacing the entire installation?

That’s impossible to delete streams references by a $ce stream (or any other stream like that). The $ce stream contain links, which just point to original events.