Issues with contact name display when on WiFi calling and traveling abroad

When on WiFi calling and travelling abroad and receiving a call, I cannot see the caller number, even if I have the number in my contacts. When I want to call it back, I can see the contact name in a Phone app, but it calls to a local country code, not the one caller is from.

Example: I'm from Slovenia (+386) and frequently travel to Croatia with a country code +385. When I'm abroad and with WiFi Calling turned on, I receive a phone call from a friend that is in my contacts (let's name him Alex). When Alex calls me I can only see his number 012 345 678 on the screen when receiving a call and I don't know who is behind this number. If I don't answer, I can see his name in the missed calls section in a Phone app. If I want to call back it gets the wrong country code as a prefix, so my iPhone calls +385 (0)12 345 678 instead of +386 ... which is Slovenian country code.

Does anyone find out what the solution would be?