Hello iPhoneUser405,
You may try swiping down to enter Control Center, as that may help to show which service/app is accessing the location at the time, as that may help isolate it down.
Be sure to also ensure you're using the latest improvements and fixes on the device by checking for any iOS updates: Update your iPhone or iPad
Update your iPhone or iPad wirelessly
1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see more than one software update option available, choose the one that you want to install.
5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
This page can also provide some help with Location Services: Turn Location Services and GPS on or off on your iPhone, iPad, or iPod touch
Cheers.