Mine does the same thing. If I open contacts from the home screen, my name is on top which has my phone number.
But if I click on the phone icon, then click contacts, it's not there.
Weird. I guess as a strange workaround, you could create a new entry and call it A and enter your own phone number in it. So next time you need to give it, click on the contact and select A as it should be on top. Other than that, I don't know how to get it to do like your other phone.