Limited Support
Our team is currently on holiday, so support will be limited during this period. Response times may be slower than usual, and some inquiries may be delayed. We appreciate your patience and understanding, and we’ll resume our usual support by the end of August.
Please navigate to Dashboard > Comments > Form admin page, edit the "Default form" and make sure it's enabled for all post types.
More info here: https://wpdiscuz.com/docs/wpdiscuz-documentation/getting-started/custom-comment-form/comment-form-settings/#post-types
Also, I'd recommend you check out the points mentioned in this doc:
https://wpdiscuz.com/docs/wpdiscuz-documentation/getting-started/missing-comment-form/