When I try to save an .ai and check "Save each artboard as a seperate file"
Illy should create each file with my chosen file name, plus appended with the name of each artboard.
Except sometimes it fails to append the correct artboard name. I always rename my artboards, and sometimes it just adds the default dartboard name.

I'm on:
2017 iMac
macOS Catalina 10.15.2 (19C57)

and,

Illustrator 24.0.3