Plugin removes the post comment box in one article

I just realised that one of my articles (the one with most comments) wasn’t showing the post comment box. I checked and the “allow comments” option was disabled. When I activated it again, WP Meta and Date Remover was automatically deactivated. If I activate the plugin option again, then the post comment box dissapears and the option “allow comments” is disabled again.
This only happens with this article, which is the one with the bigger number of comments of my blog. So I guess there is some kind of incompatibility between post comment box and this plugin when the number of comments is high enough.
Could someone help me to fix this or could the creators of the plugin fix the error?
Thank you.

The page I need help with: [log in to see the link]