Some Apple Watch 7 users report problems with charging using third party chargers after upgrading to watchOS 8.3.
Updated my watch last night to 8.3, set it on my 3rd party charger this morning, came back after an hour and it had gained maybe 2%?Reddit
Tried the same thing with my spouse’s watch and her 3rd party charger with the same result.
Put them on the official charger, zoom, done charging in no time. Argh!
Reddit: WatchOS 8.3 Killed 3rd Party Charger?
Reference: Some Apple Watch Users Experiencing Charging Issues After Updating to watchOS 8.3