The full list lives in faq-en.md.
The calendar shows no available dates at all. Usually there is no price list row for that year, or none covering the current period. Check the Price List tab and the year picker.
The price does not multiply by the number of people. The period the dates fall in has no Number of seats. The quantity mode decides what the number means; the seats field decides whether it multiplies the price. Fill it in on the period in the Price List tab.
I want to sell the same product to several customers on the same day. Set Number of seats on the price period — chapter 9. The calendar then counts free places instead of closing the day on the first booking.
Why is 18–22 August five nights rather than four? The plugin counts every selected day, the last one included. The same rule drives both the price and the stay description.
A customer cannot cancel a reservation. Either the Cancellation cutoff (hours) window has passed, or the StayNotifications module is switched off.
Reminders never arrive. A daily cron job sends them, and on a site without traffic WP-Cron is never triggered. Also check that Enable reminder emails is on and that the store can send mail at all.