Seems to conflict with threaded comments

I had this plugin installed, and people posting comments were having trouble with my nested/threaded comments on my site. When they replied to a comment, it put the comment at the bottom of the page instead of in response to the comment they were replying to.

When I disabled this plugin, everything went back to normal.

Any idea why this happens or how it can be fixed?

https://www.ads-software.com/plugins/stop-spammer-registrations-plugin/