If you're not listening to them on Starcom21, then that is your issue. Not sure if any of the old 470 MHz channels are still being simulcast (or not). Fire is still being simulcast on respective VHF repeaters.
Otherwise, I'm hearing ALL the entities on Starcom21.
As was posted a day or so ago, the STARCOM21 Site 101 (DuPage County) control channel has changed (temporarily?) to 774.18125. Make sure you have that freq programmed in your trunktracking scanner in addition to the normal control channel (773.84375).
This is assuming that you've been listening to them on STARCOM21 before the control channel changed. If not, it's likely time for a scanner upgrade.