The support document on the company’s website stated that a small number of users have experienced their Apple Watch Series 5 and SE to not charge after entering Power Reserve mode. It added that the issue is reported to occur on the aforementioned devices that are running on watchOS 7.2 or 7.3. On that note, to check which firmware is currently operating on your devices, simply open the Watch app on your iPhone or the Settings app on your wearable. From there, tap General and then navigate to the About page in order to check the watchOS version. After updating your Watch’s firmware, Apple suggests to place the affected watch model on the charger and wait for at least 30 minutes to see if it is charging normally. Should the update fail to remedy the issue, the company recommends to contact Apple Support directly so a mail-in repair can be arranged, completely free of charge. Keep in mind that Apple will still have to examine your watch first to see if it is eligible for the service. (Source: Apple Support via MacRumors)
