Why is one of my scores blank?

A blank tile names the sensor it is missing and links you straight to where you connect it, for example all-day heart rate, or it tells you it needs about two more weeks of daily data. If Trailwise's own calculation failed instead, the tiles say so plainly and offer no action link, because the fault is Trailwise's and nothing you do would help.

The exact conditions are published, not hidden. Settings > Help > How it works lists what each score needs before it appears, how your typical range is built and what it takes to draw it, what Sentinel needs and how often it fires, the constants behind the fuelling floor, and the date each figure last changed.