We’ll have to look into that specific warning. Of course, every single comment can’t have a heading (what would the heading be?). It might be necessary to change the element from <article> to something else.
For the meantime, these warnings won’t negatively affect your website.
Sorry, but this is an important detail. Pages of the site that have comments began to quickly lose ground in search results. Please tell me when you can fix this error? I would really ask you to do this as soon as possible. You are welcome.