when opening a SystemBrowser and executing a "Find class..."  command (with context menu or cmd-f with focus in the packages pane) there is a dialog listing the classes that matches whatever you type.

So far so great.

The problem is that time and again I use the arrows keys to select the one that I was looking for and press enter only to get a dialog closed in a no-op.

Note that:

1. to make that dialog work, the only way is to use the mouse to click on OK or double click the target class and

2. the input even says: "Hit return to accept"

so..