If you use the automatically installation to embed the form into a shopify page, the form will be embed into the page content by default.
Some themes have multiple page templates. For example, in the default contact page, it uses the 'contact page' template, which has the default contact form and won't show the page content. Therefore, if you publish a form on the default contact page, it won't show on that page.
You just need to change the template of the page to 'Default pape'. If it still does not work or you are not sure which template is right, please try each option one by one until you get the result you want.
Or there may be another reason. The page content was hidden in your theme. Just need to show it in the theme editor.
For the other way, feel free to contact us for support directly.