Your Samsung phone reads the phone number originally assigned to the SIM card and if you are no longer using that number (such as when you've ported over your old number to use with the new SIM card) your phone will no longer know what number your are using. Your phone in this case will list your current number as 'unknown' rather than incorrectly present the number originally assigned to the SIM card.
This information cannot currently be amended due to how the Android operating system registers a number to the handset upon first use. The issue may be resolved in a future Android software update, but until then rest assured that it has no effect on your device's functionality.
As a workaround you could create a profile in your contacts list that lists your phone's number (check with your network operator if you don't know your number). To do so follow these steps.
Touch Contacts (you may need to swipe left or right to locate it first).
3. Touch the ME entry (you may need to scroll down to locate it first). If this entry is blank you'll need to touch and hold on it instead and then select Edit.
4. Touch the pencil icon in the top-right corner of the screen.
5. Touch the drop-down box below Phone and select 'Mobile'.
6. Enter your phone's number in the empty field next to it.
7. Touch Save in the top-right corner of the screen.
Thanks for your explanation. I did ported over from old number to new number couple month ago, so I assume that is the caused of issue as per your explanation above.
However, the workaround as per above is not working on my phone. Anywhere, thanks for your helps. It's not a big deal issue, just let it be.
