[403 error] wpdiscuz-ajax.php 403

A few days ago I started to receive a 403 error in WpDiscuz related to ajax, which does not allow to display the replies to the comments.

This error seems to be related to the communication between WpDiscuz and Cloudflare, although I personally have not made any changes to either of them. At least not consciously.

You can find the comments in any post of the website. The error happens in all of them

Could you check it? Thank you in advance.