Turn OFF "Spam Box" in WHM -> Tweak Settings -> Mail.
This just allows the user to control it, but I wanted it always on and I want to forward to the ".Junk" folder anyways.
WHM -> Tweak Settings -> Mail -> Enable SpamAssassin Spam Box: OFF
WHM -> Tweak Settings -> Mail -> Enable SpamAssassin spam filter: ON
WHM -> Exim Configuration Editor -> SpamAssassin Options -> SpamAssassin: Forced Global ON: ON