WORK AROUND for anyone stuck on “Playing now”
This works for me when Battlenet is stuck at Playing now at it takes 10mins for the game to launch.
Not ideal but much quicker.
Hit play until you get to “Playing now”
Ctrl + Alt + Delete to get to the Task Manager
Then End Task to “Diablo IV Retail” (this may be hidden under the Battlenet 32bit App
Then RESTART your PC from Power Options, DO NOT SHUT DOWN just restart.
The game should then boot from the Play button in Battlenet as normal.
Not ideal but much quicker than waiting 10mins for the game to launch