April 15, 2026, 13:34 CDT—Olathe, Kansas.
Garmin is back in the spotlight this week as Forerunner users vent about lingering software headaches—months after first flagging sensor glitches. Complaints stack up: heart-rate, altitude, sleep metrics all showing erratic behavior, according to owners. iPhone users, on top of that, are still battling sync hiccups. It’s these core features runners count on for training that aren’t delivering, by the latest round of user reports.
This is a headache for Garmin, which leans heavily on the pitch that its premium sports watches deliver accurate training metrics—not simply long battery life or basic phone alerts. If heart-rate or altitude data drifts off, it throws off everything from workout intensity to recovery tips and VO2 max calculations, the go-to metric for aerobic fitness. Let the phone connection drop, and users might not get their workouts or notifications synced at all.
Garmin kicked off the rollout of software version 27.09 on Jan. 16, according to its own support pages, pledging to resolve scrolling lag, swim-related crashes, and some touchscreen glitches. Still, threads on Garmin’s forums haven’t let up. Forerunner owners keep flagging fresh headaches tied to the same update—missing sleep tracking, wrist heart-rate issues, sudden battery drops, even odd elevation data keep surfacing.
Late March saw a Forerunner 255 user reporting on version 27.09: altitude readings dropped as much as 4,000 to 8,000 below expected, GPS calibration didn’t help. Elsewhere, in a 955 thread, a user flagged that after updating, their device quit tracking sleep and picked up heart rate only intermittently through the night.
Garmin rolled out at least one more update. The Forerunner 165 support page lists version 27.10, pushed out Feb. 4, aimed at fixing data dropouts for certain devices. After installing 27.10, a Forerunner 265 owner reported that step count, heart rate, Body Battery, and other metrics were back to normal. Still, users posting about the 165 and 955 models said issues with sleep tracking and heart rate lingered.
Another issue is dogging Apple’s iPhone. Garmin forum posts from February and March flagged complaints where some watches would appear as connected via Bluetooth but failed to show up in Garmin Connect, cutting users off from syncing or notifications. A more recent thread notes the glitch persists on iOS 26.4 and Garmin Connect 5.23.
Back in February, Garmin support claimed version 5.21.3 of Garmin Connect would fix the pairing problem, sharing more troubleshooting steps with users. Still, later responses acknowledged the issue persisted. On Wednesday, Notebookcheck noted that for some, Garmin wearables paired with iPhones stayed nearly unusable—workout syncing only possible via cable.
The issue extends beyond the Forerunner series. Over on Garmin’s Fenix 8 forum, users have kept up the pressure about sleep-tracking reliability. Just this past week, a thread from April 6 included a video as proof, while another lengthy discussion claims Garmin’s sleep tracking has more work ahead—stretching complaints well into 2026.
Garmin’s software headaches aren’t exactly coming at a convenient moment. Back on Feb. 18, CEO Cliff Pemble described 2025 as “another year of remarkable growth and achievement” in the company’s earnings materials, and reassured investors about “another year of strong performance for fitness.” The company is still projecting 2026 revenue to hit $7.9 billion, after fitness-segment sales jumped 42% in the fourth quarter. Garmin
Reliability issues now go beyond just frustrating customers. Garmin faces off against Apple and Samsung at the top end of wearables. This week, Coros, a lesser-known sports-watch brand, is being positioned to runners as a budget-friendly alternative. Back in February, Morningstar’s Eric Compton noted that Garmin was gaining share in the fitness and outdoor segment.
The extent of the issue remains murky. While some users in those threads reported their watches working fine—or managed to get things back on track with re-pairing, reverting to older app versions, or updating firmware—others still faced problems. That points to glitches possibly affecting certain Garmin models or specific iPhone, app, and software combos, rather than a blanket bug disrupting all devices.
