Can't rename page in the DB version

Hello.

Today I decided to give a first try to the DB version. I created a couple of block like this:

I then opened the page:

and tried to change the page title from Title1 to Title2 but couldn’t do this and received an error:

I hope it must be a bug because I use chunked page names all the time. In fact it’s the main and the only way to structure information for me.