That sounds really strange (though maybe I'm just being dense). If you have a video, feel free to share!
Either way, see if quitting the game entirely & restarting it makes your issue go away.
I'll try to record a video next time. and maybe jump isn't the correct word to describe it, say the crosshair is on the guy before scoping in, once I ADS in it's not on the guy anymore, but somewhere above him.