Everything you ask I try and it didnt work
- I see the update on watch app, even downloaded, preparing status
- current watchOS is 5.3, IOS 13 Beta 1
- connected, paired successfully, both devices connected to same wifi a i see green phone icon on the watch
- date and time are same on both devices, synchronise with apple servers
- trying on different wifi network, same problem
- beta profile removed, reinstalled, even the watch was reset I set up as new watch same problem
One thing i notice is that when watch should restart and install the update watch didnt do that instead is restarted and watch app is froze in installing status even the watch restart - i didnt get update successfully pop up on the screen of iPhone
This seems to be exact my situation
https://forums.developer.apple.com/thread/117129