There is a known issue around this (known in the sense I know about it, there isn't an explicit issue on GitHub I can point you at).
The problem can be recreated with any node that has credentials. When you open the dialog, the editor makes a request to the runtime to get information about any credentials the node has. The dialog is not shown until that request completes. Normally it completes quick enough for the user not to notice. But if there is any delay, or the runtime isn't running, then the request hangs and the dialog doesn't open. The user then clicks again to open the dialog and it another request is sent which hangs. When those requests eventually timeout (or succeed), the dialog opens - and it'll open once for each time the user dbl clicked to open the dialog.
I've been meaning to fix this for a while as I tend to hit it whilst developing NR and the server is constantly stopping and restarting whilst I'm developing. But it wasn't something I had heard any reports of from real users - until your question here.
So please do raise an issue and we can get it fixed.