Apple Watch Series 6 – Heart Rate & SpO₂ Sensors Not Working

Hello,

I have an Apple Watch Series 6 on watchOS 26.0. Since the update, the heart rate and blood oxygen (SpO₂) sensors do not work—they don’t measure at all, neither manually nor during workouts.

However, heart rate and breathing are measured correctly during sleep tracking, and ECG measurements work as expected.

I have tried restarting the watch and iPhone and checking the sensors, but the problem remains. I can provide diagnostic logs if needed.

Please advise how to fix this or escalate it to engineering.