Amazon glitches showing a huge spike in your sales?

Does this ever happen to anyone? I woke up Saturday to Amazon telling me I had sold 21 units within a 30 minute period, all to different buyers. This is crazy because:

(i) it’s way higher than my usual daily sales (4-10)

(ii) it occurred after two days of zero sales,

(iii) it all occurred within 30 min

(iv) I only had 6 units in stock at the time (though my replenishment shipment may have just hit, thereby making me have some non-prime units available)

Many of the orders are still outstanding after a few days. I’m just waiting for Amazon to correct itself, because this seems like a glitch (too good to be true).