Ciao ​@Alexeeney. Are you recording the activity directly on your phone?

Pace relies on GPS accuracy. Maybe the issue could be related with your phone or maybe the way you take it with you during the activity.

Hello, yes both of us directly record on our phone. I've updated my phone so hopefully that might work but I don't really know what else to try! 

​@Alexeeney if you say that you ran together (i.e. same time duration) and your activity seems slower, it also means that the measured distance is shorter on your activity, correct?

Look at the maps recorded by both you and your friend to decide which one is more accurate. Sometimes non-reliable GPS creates a zig-zag path instead of a consistent line (meaning that it looks longer than it really was); and sometimes it loses signal and “cuts corners” - puts a straight line between two points but in reality, there should have been a curved path (meaning that the activity looks shorter than it actually was). 

Once you determine which device is the inaccurate one, you can try improving the GPS accuracy with it. It will never be perfect with a phone (you would need a multiband-GPS smartwatch/sportswatch for reliable data), but you can try things like - disable battery saving mode; keep the phone on an armband (vs. deep in the backpack); make sure that the app can run & refresh on the background even when the screen is off.