Hi @Anonymous ,
Where do you add your Entity form to your Web page? Through the Portal Designer or Portal Management?
Have you clicked the "Sync Configuration" button in your Portal Designer to make the changes take effect?
I have made a test on my side, and don't have the issue that you mentioned. Please consider take a try with the following workaround:
1. Go to your Portal Management.
2. Find the web page where you want to put Entity Form there under the "Web Pages" menu.

3. Click the Content page under the "Localized Content" section.

4. Within the opening Content Page, go to the Copy (HTML) part, switch to "HTML" tab, then type the following Liquid expression
there:

{% entityform name:'NameOfYourEntityForm' %}
5. Go to your Portal Designer, click "Sync Configuration" button-> "Browse website", then check if the issue is solved.
More details about Entity form Liquid expression syntax, please check the following article:
https://docs.microsoft.com/en-us/powerapps/maker/portals/liquid/portals-entity-tags#entityform
Hopes above solution could solved your problem.
Best regards,