I edited my post and it didn't register... God dammit...
Anyway, you won't be able to resolve that problem until you reach "Route 1". And even then, you can't finish that until you reach the "7th street". It's going to take a while until you reach both, so don't bother right now.
Just a tip: The end of this side thing is in the "7th street". The answer to the problem is in "South Aventurine Woods".
See you o/