Content-Tree out of sync after creating new Page

[Nikdro]

When I create a new page in the page tree, the content tree remains empty until I refresh it manually or reload the entire page. After that, it is in sync with the existing content and updates as usual.

Steps to reproduce:

1. Create new Page within Page-Tree
2. (Neos creates Page and switches to new Page -> Content-Tree is empty)
3. Add some content by clicking directly into rendered ContentCollection. (Content-Tree stays clear)
4. Refresh Content-Tree => Content-Tree is getting updated. Child-Nodes appearing
5. Adding additional content (From now, Content-Tree is in sync)

Screenshot from step 2:

Screenshot from step 5 (after pressing refresh):

No error is displayed. Also no error in JS-console. Only logs like 1 change successfully applied.

[Nikdro]

@Sebobo As discussed in Slack, FYI :)

[Sebobo]

Should be resolved via #4034 please verify after release