Based on responses and comments below, the following was the simple solution for my issue and THIS WORKED. Now my app, Match4app, is fully compatible with latest iOS versions!
- Download Xcode 10.2 from a direct link (not from App Store). (Estimated Size: ~6Gb)
- From the downloaded version just copy/paste the DeviceSupport/12.2 directory into "Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport"
- You can discard the downloaded version now (we just need the small 12.2 directory!)