Any issues with GPS on Fenix 8 / Enduro 3? (Just for Connect IQ apps)

So I've had reports that my app was consistently losing GPS positioning, but only on Fenix 8 and Enduro 3.

I got my hands on an Enduro 3, and sure enough it loses positioning all the time for extended periods of time - buy only in Connect IQ apps! Normal apps seem to be fine. My Forerunner 965 has no issues at all with the same app, same conditions.

See here (Enduro 3) all the gaps in the speed chart: https://connect.garmin.com/modern/activity/18479034851

Similar track in the same conditions at the same spot, but FR965, no gaps.

https://connect.garmin.com/modern/activity/16721160270

Another one, Fenix 7X, same conditions same spot, no gaps.

https://connect.garmin.com/modern/activity/10446310656

I turn on the positioning as suggested by Garmin in their docs, trying Sat IQ first, then All + GNSS, etc. all the way down to simple GPS .

From my logs, I can see that every time All+GNSS is picked (Sat IQ is reported by the Enduro 3 and FR965 as unsupported for some reason). Yet it works perfectly on the FR965 (and 7X before that) but terribly on Fenix 8 and Enduro 3...

Any idea?? For now I'm wondering whether Garmin got confused with the enum and is thinking All+GNSS (for apps) is actually GPS only, or GLONASS only for instance.

  • There are 3 general things involved here. 

    With some devices, you can't use constellations or configurations, and the "type" of GPS is what was last used by a native activity

    With some, they have constellations but not configurations

    And some there are configurations

    But there's more.  Not all devices with constellations support all possible constellations, and not all devices with configurations support all possible configurations

    For example, with configurations, the one that mentions L1 and L5, elsewhere is called "multi band" (the L1 and L5 bands are both used) and isn't available on all devices.  SatIQ I only see as an option in the sim, but not on a real device

    I allow users to pick the GPS "type" they want when possible, and the options, I determine at runtime.  So for example, no multi band option on the vivoactive 5 but there is with the fr965

    I implemented this a long time ago, and it was tricky!  I'm looking through my code to see what all I had to do....

  • Thanks Jim! Yep, I'm aware of these limitations - so I try configurations if the device supports them, and get the best one by default - for both the Enduro 3, F7X and FR965, this is indeed CONFIGURATION_GPS_GLONASS_GALILEO_BEIDOU_L1_L5 , which is what was used to record those tracks (I log that).

    I also have code for constellations if configurations aren't supported, but that code is never reached for any of the above devices.

    Because I'm using the best possible positioning system for the watch, I'm very confused as to how it manages to lose positioning so often... The weirdest thing is that on the recording it manages to get straight lines very wrong too (right after it had lost signal) - adding sharp wiggles to them. The FR965 doesn't do any of that and records precisely.

    I had another device with GPS on board, which recorded this track: https://www.xcontest.org/world/en/flights/detail:cuiv/9.3.2025/03:22

    That one is obviously flawless. There seems to be something very wrong with the Fenix 8/Enduro 3 series, since that's affecting me and others as well...

    I also implemented that code a couple of years ago (back when configurations were first introduced) and it was tricky at the time!

  • Understand that when using something like multi band, the battery is hit harder than something like basic GPS.  That's part of the reason I let users pick which one they want.

    Also, if you have two devices, things can be different if they are worn on different wrists as your body and surrounding can have an impact on GPS.

    And, this could also be a FW bug on the devices where you have an issue.  What if you use a native activity?  Do you see the same?

  • Yeah, agreed on the differences between devices - but I have literally hundreds of flights with the 7X and FR965 that never have any issue with GPS (using my app)... and several with the Enduro 3 that are terrible, with tons of missed GPS points. So I think I can exclude the physical location of the device... If anything the E3 should have the advantage as I wore it over my winter clothes, while typically I wear the FR965 under (on the same wrist).

    I've actually added a setting for GPS only, just to see whether that could (miraculously) perform better.

    I will need to try a native Garmin activity in flight to see - will try that next time. However, if native activities had such issues, I think we'd know it by now. So I suspect something unique to ConnectIQ apps...

  • @jim_m_58 for the fun of it I added logging of the GPS Quality (Position.Info.Accuracy) and wore both watches on the same wrist during a 30 minutes walk on a very wide riverside (no obstacles or trees nearby). I switched the position of the watches on my wrist mid way on the walk away from home, and again midway on the way back from home.

    the GPS Quality chart recorded shows the quality is a constant 4 for the FR965, with a single dip to 3 for one data point.

    The Enduro 3 during the same time (25 minutes) shows several considerable dips (for multiple data points) to 3 and 4 dips to 0 (3 of them for multiple data points).

    Of course both watches same code same settings (All+Multiband)

    There is definitely something weird going on here...

  • With the above conditions, this is the GPS accuracy recorded by the FR965

    And this is the GPS accuracy recorded by the Enduro 3

  • Jim, sorry to bother you again - I tried with a standard Hike application, and had no issues. Then I tried with your Hike2 application, and that one seems fine as well. Would you be able to share your positioning code if you have it?

  • What "type" of GPS did you have set in Hike2? (long press the middle left button before you start recoding to get the menu).  

    There's really nothing special about the code other than setting the selected configuration that I've talked about

  • SatIQ I only see as an option in the sim, but not on a real device

    SatIQ is equivalent to "auto select". Leave it to Garmin to have multiple names for the same option, in different contexts. (DCR called this out when the feature was introduced iirc.)

    https://support.garmin.com/en-CA/?faq=wgKpMjTlpV29AQB5PVvTL9

  • So what do you see in CIQ apps both in the sim and on real devices?

    Like I said, it looks to be an option for CIQ in the sim, but I've never seen it as an available option of a real devices with a CIQ app.

    The app can detect what's available, so as I've said, I only allow multi band on devices that actually support multi band and in CIQ, the name isn't multi band - it mentions L1 and L5.