Page-Tree filter does not indicate its state
In TYPO3 until v8 an info-box informed the user about an active page-tree-filter. (see screenshot attached)
I don't see this box in v9 or v10 anymore.
It's a mix of regression, bug and missing feature.
Someone may removed the info-box intentionally. But for me it's kind of a bug - it was there and is gone now.