P,
Thanks for using our plans!
I’m confident the missing piece is that you have not yet adjusted your Pace Zones in TP to be 80/20 zones, to TP is way off in the predicted pace. Be sure to review our document Understanding Your TrainingPeaks Structured Workout Plan https://www.8020endurance.com/understanding-trainingpeaks-workout-plan/ and set your 80/20 Pace zones (not Default Pace, actual Run Pace) and that prediction will be much closer.
The predicted will still be off, as TP assumes you will run at 75% penetration into your zone, when in fact you could be at 1% penetration of the zone and still be following the plan precisely.
In fact, just ignore predicted pace in TP, it is not necessary nor helpful.
David