Why contacts saved with international dailing codes not showing on calling id as local calls?

[WarCoffers]

All my Contacts are saved with the international dialing code format (+231 *** etc). Local calls received, which come without the international dialling prefix, only number shows, no contact name though number is in my CONTACTS. All SMS Text and all international calls are okay, as these come with the international dialling code and phone recognises the number and Contact. Currently, the only workaround, which I find unacceptable, is to save the Contact name and number twice, once with the international dialling code, and another as it would be received as a local number. This is unacceptable, as it would mean doing this for every single number I have, otherwise when I travel the overseas numbers (now local) would not show a Contact name. So grateful if someone has a solution (without ROOTING my phone), otherwise I will have to give up my beloved S7 Edge.