Offline editing

I've just installed newest udated version now in July 2022. It says I have LR 5.4 on my MacBook Pro M1 (OS 11.6.1).
I have always been able to edit photos offline with LR before. Now, as soon as I am not connected to the Internet (LR still open) there is comes up a big black square on top of the photo so I can't see it. The big black box says:
"No Internet Connection Available. Lightroom is running in offline mode. Reconnect to the internet network or try checking your internet cables and router." 

I try to restart LR with no WiFi but each time same big black square over the photo!

Before my update last week, it worked very well, so I wonder if this is a bug? Before, I could edit offline and later, when I was online again, it was syncing to the cloud. Exactly what I loved! I very much need offline editing possibilites in my work, so why istn't it possible with the newest version of LR any longer?
Leon Schulz