My iPhone 6s GPS is Far Out and it has encountered an iss with maps

Using IOS 11.4.1 and maps is driving me insanely mad. My location is completely out. I used two iPhones side by side. On my left was a iPhone 7. On my right my iPhone 6s. At the same location. The iPhone 7 - GPS works correcrly. My iPhone is totally out almost a kilometre out. Logged a call with Apple support and they ran Diagnostics checks to see if the phone has a GPS chip that is all but does not check the functionality as such. So mobile inspector diagnostics from Apple is a False Report. They said there is no issue with my HW. But comparing 2/3 iPhones at the same location tells me a different story.

Only to realise it is the phone that is the problem. I also went to extreme of changing Service Providers issue.

.When I was Driving and using maps I went in circles missing turns and so forth. A huge disappointment from Apple but they don’t care do they. Winch all you like it falls on deaf ears. .

It’s apple way to upgrade your existing iPhone that is the only logical explanation