This is very similar to me…
Resting – 43bpm
AeT = 156bpm
AnT = 187bpm
Max = 202bpm
With me there’s no in-between – I can either comfortably run at a semi-decent pace under AeT or run at AnT. At the last marathon, my avHR was 178bpm.
You’re right, it does seem high, I’ve started training at low Z2 (145bpm) hopefully that’ll continue to push everything up and reduce the training stress… hopefully.
Sorry I don’t have much insight, other than to let you know you’re not alone:)