I have the same thing, but with PayPal. My full namesake has created another account, and used my email there - so I guess he is not getting any notifications. I am afraid to contact PayPal support, since they might just go ahead and block the wrong account, or both of them, so I just ignore these emails from parallel universe.

I was able to shut down a couple of Instagram accounts that were using my email though. Instagram does not verify emails, but fully trusts them to reset your password.