
ⓘ Garmin
Garmin has started rolling out a new stable update to several of its flagship smartwatches. Arriving in the wake of numerous complaints about ongoing software issues, the new update promises to resolve a recent heart rate sensor issue while making other notable improvements, too.
Garmin has returned to its last-generation flagship smartwatches with a new update. For context, the company began rolling out System Software 23.39 to the Fenix 8 on September 25.
48 hours later, it delivered the same update to the Fenix 8 Pro. As we discussed at the time, System Software 23.39 was the first 23.xx-based stable update for Pro-branded smartwatches, with Garmin electing against releasing System Software 23.31 to the Fenix 8 Pro or any associated smartwatches.
Now, it has returned with System Software 23.40. At the time of writing, the new update has only officially reached the Fenix 8 and the Tactix 8 (curr. $1,299 on Amazon); the Quatix 8 does not have a dedicated support page where Garmin posts firmware updates.
As a result, the Fenix E and Fenix 8 Pro remain on System Software 23.39 for now. The same is the case for the Enduro 3 too, which Garmin has kept on a different release cadence lately. The company has not suggested when System Software 23.40 will be available to these smartwatches, either.
Seemingly, System Software 23.40 does not contain a fix for a recent display and battery bug that it had promised on October 7 to release 'with the next software update'. Instead, Garmin has focused on resolving a bug that prevented the Fenix 8 family's optical heart rate sensor from working. The full changelog between System Software 23.39 and System Software 23.40 is as follows:
- Fixes crash when enabling active heart rate broadcasting via GCM.
- Fixes optical heart rate sensor not working.
- Fixes other minor issues.
- Fixes silent mode not muting notifications.
Alex Alderson - Senior Tech Writer - 15429 articles published on Notebookcheck since 2018
Prior to writing and translating for Notebookcheck, I worked for various companies including Apple and Neowin. I have a BA in International History and Politics from the University of Leeds, which I have since converted to a Law Degree. Happy to chat on Twitter or Notebookchat.
Alex Alderson, 2026-10-14 (Update: 2026-10-14)

