BUG: Intrest not accruing

[PTTG]

I've yet to receive interest on any level... I thought that it was accrued whenever a unit gets killed or something like that, but the guide says it appears at the end of each wave. That definitely doesn't happen.

Or maybe it is... I see... it's at the end of a wave, but not the start of the next one. If it was at the start, then you'd get a clearer idea of how much you earned, and any upgrades you make subtract from your interest.