Mileage incorrect

[WhiteBearTommy]

I just completed a run - distance between 4-4.5 miles. App shows just over 7000 steps so around what it should be.

However, the app shows I ran 11.18 miles, including one mile at a world class rate of 1:35!

Setting aside the humor - WTH?! First time this has happened. Usually maps are very accurate (use gps), but now the map doesn’t show me anything other than the mile total. Battery strength is medium, so that’s not issue.

Thoughts? How do I fix before next run?

[SunsetRunner]

@WhiteBearTommy 

The GPS setting on your Charge 5 is it set to the default dynamic GPS or one the other settings: Built-in or Phone.

Dynamic: uses both the Charge 5's GPS chip AND the connected smartphone's (when present) GPS chip.

Built-in: uses only the Charge 5's GPS chip which is easily affected at times depending on obstructions to the sky or tall buildings (because it has a small receiver).

Phone: uses only the connected smartphone's GPS chip (when present). Accuracy is dependent on the phone's hardware.

Dynamic is a good option as it uses which ever device's chip that has the strongest GPS signal to the satellites.  Regardless errors can happen it this may have been a fluke. Some GPS chips have better checksums than others below is some information that you may find useful.

https://www.gps.gov/systems/gps/performance/accuracy/

[SunsetRunner]

Change the GPS setting to use your phones GPS and take your phone with you.  The inbuilt GPS is known for being inaccurate depending on how you wear your device.  I like mine tight and about 2 fingers above my wrist bone as I use HR as guide when running (Maffatone method) and this is the only way to get accurate HR.  The issue with having it tight means the GPS doesn't track correctly as there is no space between your arm and the GPS receiver under the watch.  I've always used the phone GPS option and it's always matched my Strava.

[WhiteBearTommy]

I guess I’m a little slow on the uptake 😉

I start my runs with the Charge 5. However I always have my phone with me. Looking at the app I can’t figure out how to choose the GPS “source” (it’s kind of a crappy app from the perspective of changing settings). But it does seem one option is starting the run from my phone, but that seems to defeat the reason for the watch. 
This is the first time it’s happened so I wonder if it’s a one time glitch. I do know that when I started running the watch vibrates a few times early on, but I ignored it (not wearing glasses when I run makes it difficult to read anything on the display).

Anyway any additional thoughts appreciated.

[SunsetRunner]

@WhiteBearTommy The setting to designate your GPS source is on the Charge 5 itself. Just go to "settings" and swipe to GPS tap to select and then tap again toggle through the options.