Sorry if I'm not explaining this well as I'm pretty new to the whole flight sim experience. I'm running into an issue where, for example, leaving KATL heading north the Center frequencies are not having a hand over like they should. I'm flying from KATL to KSTL, over Nashville, and the Center frequency intersects the ATIS for Nashville for a while before I finally get the hand over pop-up or call from Atlanta Center to change over to Memphis Center.
The route I was flying was KATL/09L PENCL2 JAACE DCT BNA QBALL1 KSTL/I06, and the handover to Memphis didn't happen until i was about 5Nm after BNA, where as (from how I understand it) the FIR changed from Atlanta to Memphis approximately 25Nm before JAACE.