Abnormal battery drain while powered OFF (9% per night)

Hi everyone,

I'm experiencing a serious and well-documented battery drain issue on my MacBook Pro M3 Pro 14" and I'm hoping someone has encountered the same problem.

The issue: My MacBook loses around 9% battery in less than 24 hours while completely powered off. The battery health is at 100% with only 26 cycles, so the battery itself is essentially brand new.

When it started: The problem appeared immediately after upgrading to macOS Tahoe. Apple Support asked me to downgrade back to macOS Sequoia with a clean install — I did exactly that — but the problem persists on Sequoia as well.

What I've already tried (all failed):

• Clean reinstall of both macOS Tahoe and Sequoia
• Safe Mode, disabling Find My, Wi-Fi and Bluetooth OFF before shutdown
• Force shutdown via 10-second Touch ID button press
• Multiple pmset commands: hibernatemode 25, tcpkeepalive 0, powernap 0, proximitywake 0, womp 0, darkwakes 0
• launchctl disable on osanalytics and calaccessd services
• Apple Hardware Diagnostics → no hardware issue found

What I discovered: Running sudo pmset -g sched reveals two scheduled system wake events every night that resist all suppression attempts:

com.apple.osanalytics.hardhighengagementtimer com.apple.calaccessd.travelEngine.periodicRefreshTimer

Only sudo pmset schedule cancelall removes them temporarily, but they come back after every reboot.

The root cause identified: Running pmset -g assertions reveals the real culprit:

pid 129(powerd): UserIsActive named: "com.apple.powerd.ws.initialize" — active since boot, never terminates.

This assertion normally ends within seconds of startup. On my machine it stays active permanently, keeping UserIsActive = 1 and PreventUserIdleSystemSleep = 1 indefinitely — even with the lid closed. This prevents the shutdown sequence from completing properly, leaving the Mac in a semi-active state that drains the battery overnight.

This behavior is identical in Safe Mode, which rules out any third-party app.

Has anyone else seen this on M3 Pro with Sequoia or Tahoe? 

Reminder : Apple Engineering did not come with a solution yet.

Thanks