I think One Last Kiss is actually the reason why Try is moving up relatively slow. People seem to forget that it was a Radio smash because of its somewhat low digital sales and a #5 Hot 100 peak.
Radio isn't ready to completely let One Last Kiss go...
The HAC Rate thing isn't exactly helping either. Try is #1 but One Last Kiss is #2 so they are slowly dropping it on HAC. It's still #6 on HAC Radio and #11 on Pop
I think if (when) her AMA's performance goes well Radio will jump on board faster