Apple ID Sign In Requested

Hello,

Can anyone help me figure this out? I keep getting these notifications on my iPhone, iMac and MacBook Pro.

Several weeks ago, I sold my iPad Pro 12.9 to upgrade to the new one. Before selling the iPad, I turned off Find My and signed out of iCloud before erasing and resetting the iPad. I also removed the iPad from my devices in iCloud.

The same night after I sold the iPad, I started getting these notifications. I was concerned that maybe I did something wrong and I didn’t actually erase the iPad or it somehow was still attached to my Apple ID because the location was very close to where the new owner lives.

Later, I figured out that my IP address sometimes shows my geolocation to be in the city that is showing up in the notification.

After a few days, I stopped getting the notifications and everything was fine. Now, several weeks later, the problem has reappeared.

All of my devices are accounted for and they are signed into my Apple ID. They all show up in their correct GPS location in Find My on iCloud.com .

When I receive these notifications, I look at all my devices and none of them are requesting to sign in and none are giving the prompt to enter a verification code.

I have these devices:

HomePod

2 Apple TV 4K

MacBook Pro

iPad Pro

AirPods

AirPids Pro

iMac

So, I have a couple of questions:

1. Is there a way to tell what device or what type of device is requesting the sign in?
2. Is there a way to get an IP address of the device requesting to sign in?
3. How do I correct this problem if it is actually one of my own devices requesting to sign in?

I appreciate anyone who can help me get rid of this frustrating situation. It happens every few minutes and it is really annoying.

Thanks!!