Like others, I have been having a multitude of issues with Apple Watch series 3 since updating to watchOS 7/7.0.1. The primary issue has been the watch shutting down numerous times per day and displaying the low battery icon. When putting the watch on the charger it powers on at >90% battery life.
The secondary issue(s) have all been tied to fitness, heart, and health data not working. Compared to a watch that can’t stay on for normal periods of time these issues are not the primary concern.
After running a complete restore of the iPhone and Watch as outlined in the KBase article, nothing has improved.
I had a tech support session with a representative via Messages. They ran a remote diagnostic which did not detect any battery or hardware defects. They encouraged mailing the watch in or visiting the Genius Bar, however neither option will be able to fix a software issue outside of doing an erase / restore which has already been done multiple times.
At this point my only options are 1) bring the watch to an Apple Store for further evaluation, or 2) wait for the next watchOS update and hope it fixes the issue.
I’ve been an Apple Watch user since it was first released. Due to this issue my watch is completely unusable and sitting on my desk until it can go 8+ hours without crashing. Over the past 5 years this is the longest period of time that an Apple Watch has not been on my wrist. My disappointment with watchOS 7 product quality is only eclipsed by my anticipation of the next watchOS update.