Samsung’s rollout of the One UI 8 Watch update is hitting a snag, specifically for owners of the Galaxy Watch 4 Classic. According to a wave of reports on Samsung’s official community forums, the update—which was intended to breathe new life into the aging wearable—is instead causing critical health sensors to fail.

Built on Wear OS 6, One UI 8 Watch brings a refreshed interface and performance tweaks. It is widely considered the final major feature drop for the Galaxy Watch 4 series, designed to extend the lifespan of the device. However, for a vocal group of users, the update has had the opposite effect.

One user based in India detailed the issue, noting that after installing the update, key sensors on their Galaxy Watch 4 Classic simply stopped responding. This includes the wrist detection, the Bioelectrical Impedance Analysis (BIA) sensor, and the ECG monitor. The user shared screenshots from Samsung’s onboard diagnostic tool, which confirmed multiple sensor errors.

In a bizarre twist, the user discovered that the sensors briefly resumed functionality when the watch was worn on the inside of the wrist, rather than the standard position. This quirk has led many to suspect a software bug rather than a sudden hardware failure. Unfortunately, standard troubleshooting steps—such as factory resets or clearing the cache—have reportedly failed to fix the problem.

The comment section of the original report is filled with similar complaints from other Classic owners. Interestingly, the issue appears to be isolated to the specific "Classic" variant; so far, there have been no widespread reports of the standard Galaxy Watch 4 suffering the same fate.

While Samsung has yet to issue an official statement regarding the glitch, there are signs that the company is taking action behind the scenes. Reports suggest the rollout has been paused, with many users noting the update is no longer available for download despite being accessible just days ago.

Until Samsung provides clarification or a hotfix, Galaxy Watch 4 owners—particularly those with the Classic model—are strongly advised to hold off on installing One UI 8 Watch to avoid losing essential health tracking features.