I have Watch Ultra 3, and when I set them to charge, they are just not starting to charge and they can be there for hours. They start charging only if I do restart.
Frimware is lastest.
Is it a bug?
(Using an original fast charger that came with it and good USB-C brick)
Apple Watch Ultra 3, watchOS 26
See especially “Optimize battery charging” here. Perhaps your Apple Watch has learned your charging habits and therefore delaying the start. If you don’t wish to proceed that way, stop the optimization.
Charge the battery on Apple Watch - Apple Support
See especially “Optimize battery charging” here. Perhaps your Apple Watch has learned your charging habits and therefore delaying the start. If you don’t wish to proceed that way, stop the optimization.
Charge the battery on Apple Watch - Apple Support
Watch Ultra 3 does not charge right away
