Ahhhh, no I did not. I had removed both the bell wires and the resistor. After adding only the resistor back to the bell terminals, the Hardwire Translator status changed to Active on the panel and the LED on the PG9WLSHW8 is now flashing green!
Any idea why the siren would be causing this? Is it still possible to wire my siren to the PG9WLSHW8 or am I SOL?