Some grid points show 20+ or no result
What 20+ and a missing point mean.
A point marked 20+ means the business is not in the top 20 there, which is exactly what the heatmap is meant to reveal. A region of 20+ points means low visibility there.
A point with no result could not be measured after retries: it is left out rather than guessed, and its credits are refunded.
If every point shows 20+, check the keyword and that you picked the business, not a city or area.