Infinite Loading Screens
Network issues are the most common cause, though others report issues, and anet are certainly actively working on the problem. I’d follow the guide at https://www.pingplotter.com/fix-your-network — and make sure you track down to the instance servers — to see if you can isolate where it happens.
If it is showing that the network connection is fine, or that packet loss is in the anet area, a support ticket is the place to go. (If you open one now, they will ask you for the equivalent of that guide in diagnostics as step one, hence my suggesting you start there.)