[Neos] Structure Panel show removed Content Collection

[Maxi milian]

I created a Content Collection "teaser" within page.body.content in Root.ts2. It is available in backend structure panel as "Content Collection (teaser)".
If I removed this Content Collection in Root.ts2 and Template it is still shown in structure panel after I cleared the cache and signed in backend again. What should I do?

It is also possible to sort order of Content Collections in structure panel?