remove (Leave a Reply) only sometimes works

I solve this problem differently since I refuse to change WordPress Core files as the changes disappear every time WordPress is automatically updated.

I’ve used this plugin in the past:
https://www.ads-software.com/plugins/disable-comments/

I have also used this setting when I first start a new site:
“Allow people to post comments on new articles” described here:
https://codex.www.ads-software.com/Settings_Discussion_Screen

For existing pages, I’ve used Quick Edit when there are a small number of them, to disable commenting:
https://codex.www.ads-software.com/Pages_Screen

And, for large numbers of Pages, I’ve done mass updates of the WordPress database.

But the plugin I named first does a nice job, though deactivating it will allow comments.

Thank you,it works