Can't select target post

I am able to select the source posts and comments with no problem, but I can’t select a target post.

I see Target: and then the dropdown to Select Post Type. However, the place where it looks like I can’t select the target post is behind the Perform Action button. I tried clicking Perform Action anyway just to see if there was a second chance, but all I got was the message that I needed to choose a target but with no option to select one.

I am using Chrome browser.

https://www.ads-software.com/plugins/copy-or-move-comments/