DAHDI Fax Detection Time

I have fax detection enabled for the inbound routes on by T1/PRI, and if I set the detection time to 10 seconds (which is actually closer to 15) it will work. However, no one is going to wait 10-15 seconds before even hearing the first ring. I have another freepbx at another client with the same T1/PRI provider and the fax detection works with only 4 seconds of wait time. Any guesses?

FreePBX 13.0.95
Current Asterisk Version: 11.19.0