+ sign should be removed by default in page names

Not sure if "Wiki" is the right "Component", please reassign as desired.

In my installation, renaming can make a page inaccessible...

Example: A page named A + B. When creating it with directly this title, the + will be replaced by a space from the beginning, and the created page will work fine.

However, when renaming an existing "innocent" page to A + B, it becomes inaccessible in my installation.

See attached screen recording for a demonstration.

Bonus question: How can I delete this page again if I don't have a parent node which I can "delete recursively"?