If you have updates to install, select a few of them to be installed. Now wait for the task to finish and then press "install more updates" or whatever the button says. Now you are back in the package list. You will see the remaining packages, but the info pane shows the info of one of the already installed packages.
Created attachment 310496 [details] Screenshot
Fixed upstream in 69950ece2cc58e6ca0a6dc1b3e16697b9744f712, many thanks. Richard.