I do the following:
I scan files and saved then into a file called multipageproject.pdf
Then I rename the file via Dolphin function Rename.
Then I scan the next pages and store them, and so one.

If i do a short brake, then continue doing it, Dolphin is not able to list this file in its browser. the file is there: visible in console via LS as well as if i try to save it again.

If i do a search with "multip" then the file is shown, but after some further renaming, the file is not showing in the search view too.
Ah, when I shutdown Dolphin and start Dolphin again, then the file is visible again.

I'm using SuSE Tumbleweed