Solution: for all category pages

/vendor/magento/module-catalog/view/frontend/layout/catalog_category_view.xml. add line close to bottom of fime

    </referenceBlock>
     <referenceBlock name="page.main.title" remove="true" /> 
</body>

Solution: for individual pages

go to admin->content- > pages ->design section and paste in the xml <referenceBlock name="page.main.title" remove="true" />