Troubleshooting wrong coordinates

I have noticed a few photos that don’t have correct coordinates. There have been a few instances where the tech goes from one work site to another, but the change in location seems to lag, causing a few photos from the second worksite have the GPS location of the first site. The two sites are not necessarily close (the instance of this that I noticed most recently, the two sites were 20mi apart). My guess is that the phone lost its GPS connection and used it’s last known location. I am not actually sure how often this happens because most of our photos look very similar, so I wouldn’t necessarily notice, but the clients would and we are using the location metadata to confirm which project photos go to, so it is important that we get it right. How can we keep this from happening in the future? I would rather have no location data than wrong data. Is there perhaps a phone setting that could improve this? Again, I don’t know that this is a widespread problem, I have only noticed it happening two or three times. But there could very well be other instances that I am not recognizing as problems.