Somebody is logging on with my apple id,

I think what donv is referring to is if this is an e-mail you received, or a popup on the screen, about the time you were actually logging in, there is probably nothing to worry about. The location in the e-mail is where your ISP reported it. If their servers are in a location distant from you, there will be a large error. Based on other posts I have read, the distant error can be very large.

Yes, that is what I was talking about. Did you see the last disappointing installment here (on the 2nd page): https://discussions.apple.com/thread/251135945

I don't exactly remember the reason (maybe something about a distant server). But, Eric Root indicated that was is happening to you is not a problem, and he knows.

I believe that is what Eric said. And, you are welcome.

You are very welcome.

I saw that and since it matched what léonie posted earlier, I didn't have a response. What you saw appears to be normal based on léonie's response and yours.

You are welcome.