In addition to releasing watchOS 7.3.1 , Apple has published a support document offering details on what to do if your Apple Watch Series 5 or SE won’t charge.
Apple says “a very small number of customers” with these models running watchOS 7.2 or 7.3 have experienced an issue with their watch not charging after it enters Power Reserve. To check if your Apple Watch is affected by this issue, place your watch on the charger that you normally use, then wait at least 30 minutes.
If your Apple Watch still won’t charge, contact Apple Support to set up a mail-in repair free of charge. Your watch will be examined before service to verify that it’s eligible for free repair.
