Hi,
We would like to reproduce this problem. Can you provide me the Wordpress version you are using?
Do you use any other plugins? It may be possible there is a conflict with another plugin.
Can you check or you get any errors when you try to insert a new product link in the developers tools of the browser. Depending on the kind of browser you use you can press on F12 and de developer tools will show up. Check the console tab or there are any errors and the network tab to check or all files are loaded.