I don't know if anyone can ID exactly, but must be one of those small "Thai" type cayenne. Plants are usually smaller, peppers are small and usually quite hot. What source did you get them from?

purchased on eBay from a seller. So not too surprised that it got mixed up somehow. They are actually very tasty and productive. Currently drying about 40 peppers for a batch of crushed red pepper.

Sounds like a great plant and nice variety with the smaller leaves. Too bad we don't know what it is! Have you looked through what the seller offers to see if anything looks like what you have? Or reached out to them to ask what else it might be?

If you can't identify it, you might want to save some seeds so you can try to grow it again!

Hinkelhatz hot pepper may be your pepper. About an inch in diameter, with a scoville between 5000 to 30000. You said it had the heat of a jalapeno and they have a scoville between 5000 and 10000, so using the the big list of hot peppers I searched in the Jalapeno scoville range. could be yours.