If I edit the current clipboard text and press 'OK', the menu that opens when we click 'invoke action' gets opened.
This only happens if the copied text is a URL.
I can reproduce. Copy a URL, edit that entry, click "OK" in the edit dialog and you get the invoke actions popup.
The issue is that when you do it from Klipper (the standalone executable) it has a blacklist so that when the active window is e.g. "klipper" (the popup menu) it will not invoke the actions dialog. HOwever, if done from plasmashell, this does not hold and the actions dialog shows up.