A Galaxy S25 FE user blamed One UI for battery drain, turns out it was something entirely different

It’s often easy to blame the latest software updates for poor device performance, but that might not always be the case. Just like that, a user recently thought a recent One UI update was making their Galaxy S25 FE run unusually long and hot, but later discovered the culprit was something entirely unrelated.

Reddit user Jabbadava recently reported “severe battery drain” and “overheating” on their Galaxy S25 FE, even while it is idle. The title mentions One UI 9 and makes the recent beta rollout for the Galaxy S25 series look like the culprit that could have detrimental effects on the device’s everyday performance.

In the post, however, the user explains that the cause of the battery drain, as they determined, is a background service that kept waking WhatsApp on their device. For instance, the user points out that WhatsApp remained active in the background for 14 hours a day, with over 2 hours of cumulative active CPU usage. Analysis of the Android JobScheduler dump showed that WhatsApp’s internal contact sync was failing and immediately retrying.

They also mention One UI 8.5 with an August security patch in the post, contradicting One UI 9 in the post’s title.

While that was the user’s initial diagnosis, it turns out neither WhatsApp nor One UI was to blame. The user later discovered it was because they were running MicroG, a pseudo-implementation of Google Play Services required to run modded YouTube clients such as ReVanced or Morphe for YouTube. Since this unofficial Play Services ran alongside the official version, it deceived WhatsApp into believing it was the real deal. As a result, WhatsApp background features endlessly tried to get a valid pass from Google services but couldn’t get one since it was trying to reach the unofficial one.

The fix for the user’s issue was ridiculously simple: they uninstalled MicroG, closed WhatsApp, and cleared the cache. The solution returned to culling all those background calls from WhatsApp and removed any instances of excessive usage.