detect tempo of selected region moves region

I used the detect tempo of selected region on a kick drum track. It detected 87-good so far. then when i click OK the region slides to the left so it starts before the downbeat. I tried this multiple times but with the same result. Flex time is not enabled, I didn't change the tempo yet to match up with the kick.... I even moved the track back to the downbeat, did the same detect tempo function and clicked OK---it moved again. anybody have a clue about this?