Hi
@MedicinaIKFC,
I've helped several friends to unlock the dog tag, your issue, I think, is a simply connection issue
For your second question: Yes you can rent your own server (the server will must be open)
Another suggestion I can give to you to avoid the problem is to hunt the dog tag with some friends so if you lost connection you will re-join and continue (who make the last click catches the dog tag no matter when he join the game)
If you want and you are on PS4 I can help you
just DM to me
Navigando
If it was useful, please Grant XP and accept this Answer as Solution
[I do not work for EA!]