Stuck in town

[Sugary]

Saw a thread about this very same issue, but that had no answer whatsoever.
I'm stuck on the side quest where you have to find Cylinder. Following a guide, I talked to everyone in town for hints of his whereabouts.
So I did.
And nothing happened.
I read that Cylinder is supposed to appear leaving the mines after you've talked to everyone, but that didn't happen. I'm not entirely sure, but I think it's because Poco is in Fan's shop stealing cakes, making Fan repeat her line about disappearing cakes instead of the flag I need to find Cylinder. This should be easily solved by giving Poco his boombox so he'll return to the village.
Unfortunately, I can't do that because the game won't let me leave the town, and consequently, give Poco his boombox, until I find Cylinder.
So I can't find Cylinder until I give Poco the boombox, but I can't give Poco the boombox until I find Cylinder.
Essentially, I'm softlocked.
Help.