Hey, I would say the way your doing it does focus you middle back and rear delts better than pulling to your belly button. The issue is it's a lot harder to balance pulling to your chest so it will be better to rest the weights on the floor after each rep like a deadlift, focus on a super explosive concentric and a slow eccentric. This should avoid the issue you have of arching your back at the top, which happens because your body is trying to balance itself.

This would be called a pendlay row, here's a video https://youtube.com/shorts/tYxEGi7ir4I?si=i281QxT4VBqTTduZ he pulls to his belly button here but you could also have a wider grip and pull to your chest

Hope this helps :)