According to the company, the update includes a fix related to Low Power mode for Apple Watch Series 5 and SE users.
Apple officially released watchOS 7.3.1 for all users.
According to the clangelog of the new version, the update solves a problem that prevented the charging of some Apple Watch Series 5 and SE after activating the “Low consumption” mode.
The watchOS 7.3.1 update can be downloaded for free via the dedicated Watch app on the iPhone by going to General> Software Update.
To update to the new software, Apple Watch must have 50% charge level, must be placed on the charger and must be within range of the iPhone.