No.52919
The creator won't show up immediately, it's intentional because if it did they would immediately invalidate what you imported with their army of snitches and cocksuckers lurking on matrix and this chan.
Use your import log and browse posts from there. If it returns an error don't panic it's not cached yet, bookmark and wait a while, remember to check periodically if it's stuff like external links. If it shows Artist's page, the creator isn't fully indexed (only for completely new database entries), once the creator's name shows up you're good.
tl;dr: Long cache is long. You did nothing wrong, just wait. You can't force a cache refresh afaik at least not anymore.