iPhone 6 GPS doesn't work after a screen replacement

Hi guys, two weeks ago I took my iPhone 6 to an apple store for an off-warranty screen replacement. They replaced the screen ($130) which works great but since then my GPS has been EXTREMELY inaccurate like 3 miles of error. And also, the little arrow that supposedly points to the front points in any random direction while I move.
I use the GPS a lot and it never ever had any issues until now and I know it's weird af but I can't think that the screen replacement and the GPS issues are unrelated.. It's such a coincidence.

Right now I'm in south america on a business trip and I will need to buy a new phone to use the gps because of this

This is an i6 on iOS 9.3.1, I don't want to update to iOS 10 (I don't like it) and I would prefer not to restore the phone to factory settings since I have 40GB+ of downloaded music on Spotify that I wont be able to re download until I'm back in the states.

I already tried reinstalling google maps, resetting the network settings, toggling the location services on and off like 57 times and multiple hard and soft resets.

Any help would be very appreciated!

 

I've been doing some research and I found that it's 90% probable that the cause of this issues is the Wifi/Bluetooth antena flex. Something I can replace for les than $20 but apple will sure want to replace my phone for $299.. Even tho my phone was working perfectly before they opened it and I already payed $129 for a new screen 10 days ago.