XATA = Blank calendar with Training Pacer on Training page
XFAI = Populated forecast with 3-day window on Training page
Magic Buckets doesn’t need the workout selected to run on its own, but relies on the workout specs such as Mixed Rouleur (6 minute power) and XSS comprised of low, high, peak strain points.
Or do you intend to run the selected workout on EBC (or elsewhere) while you monitor how Magic Buckets tallies XSS on your Garmin?
What is the workout you selected and what is shown for low, high, peak values compared to what Magic Buckets displays on your Garmin?
For example with the followig workout Magic Buckets should show 40 / 3.8 / .8 for low/high/peak and interval target watts will be around 6-minute power.

While some content is outdated you should find my newbie tips of value – Onboarding steps for Xert trial users and newbies - General - Xert Community Forum
