If your Fenix 8 stopped tracking your heart rate, Garmin update 23.40 fixes that failure. The company began a phased rollout of System Software 23.40 on October 13, starting with 20 percent of eligible watches and expanding from there.
For gym goers who rely on their watch during training, this is the version to install before assuming the sensor is broken hardware. The fix targets watches where heart rate measurement stopped entirely, not watches producing inaccurate or intermittent readings.
Fenix 8 Stopped Tracking Your Heart Rate? What Update 23.40 Fixes
Gadgets & Wearables reports that update 23.40 fixes the heart rate failure that surfaced after version 23.39 rolled out in late September. On affected watches, the green and red lights on the optical sensor went completely dark, and wrist heart rate readings disappeared from both everyday tracking and recorded workouts.
Garmin’s changelog names the problem directly. Version 23.40 fixes the optical heart rate sensor not working, fixes a crash when enabling active heart rate broadcasting through Garmin Connect Mobile, and fixes silent mode failing to mute notifications.
Garmin’s announcement covers the standard Fenix 8 AMOLED models, and the same stable release is also reaching the Fenix 8 Solar, Enduro 3, Fenix E, Tactix 8, Quatix 8, and D2 Mach 2.
The changelog makes no claims about inaccurate readings, intermittent gaps, or problems with external heart rate straps. If your watch still shows a pulse but the numbers look wrong, this update may not be your answer.
What To Know Before Installing Garmin’s Latest Fix
Version 23.40 is a stable release, not a beta, and the rollout is gradual, so your watch may not have received it yet.
Here’s how to get it:
- Check manually on the watch by opening Settings, selecting System, choosing Software Update, then Check for Updates.
- Use Garmin’s instructions for updating through Garmin Express if you prefer installing from a computer.
- Confirm your installed version under Settings, System, About to see whether you are still running 23.39.
If installing 23.40 does not restore your readings, Garmin’s troubleshooting guide for missing heart rate data walks through sensor cleaning, fit, and settings checks.
When you contact support, have your model and software version ready, and describe whether readings disappear during everyday wear, a recorded activity, or both.
A separate monitor is another option if you need heart rate data for training while you wait for the rollout. Our guide to heart rate monitors for different workout types covers chest straps and armbands but remember to confirm compatibility with your watch or training app before buying.
The bottom line for affected Fenix 8 owners: 23.40 is live, it is a stable release, and Garmin’s own release notes confirm the heart rate failure is fixed.
