As mentioned in the title, I am having trouble updating my Apple Watch Series 3 (WiFi model).
Currently I'm running iOS 12.4 on my iPhone XS and on Apple Watch running watchOS 5.1.2.  Although connected to WiFi, the Clock app states that the download of the firmware is paused until I connect to a WiFi network. I'm sure my phone is connected and I checked the download speed which is around 100 Mbps.
I've already started on both clock and phone.
In addition, I noticed the battery life of my watch over the past few days. Usually I got two days without charge and today it has lost over 20% overnight. I don't know if this is part of the problem, but I hope this gets better with watchOS 5.3.
PS: I'll be back in the morning because it's getting late. I quit anyway because I saw so many people active right now.