Dear Bullo,
We are glad to help you and we may need some more information for confirmation.
From your description, it seems that you create the app from Integrate>PowerApps>Customize forms from a SharePoint Online list.
If yes, could you upload some screenshots showing the issue in your environment for our reference?
Note: Remove any private information before uploading the screenshots.
I just create a list like the following.

PowerApps

The custom form when creating a new item in the list.

Do you mean that you see the behavior like what is showed above? If yes, it seems that the UI has been changed.
If it is convenient, you can let the users access the new form via the URL https://contoso.sharepoint.com/sites/sitename/Lists/listname/newform.aspx directly to see the outcome.

As our product developers are willing to listen to users' requirements, I suggest you send your feedback and pass on your suggestions to our new feedback platform mentioned in the following article so that product developers know your suggestions and feedback to improve the product.
Submit feedback for Microsoft 365 - Microsoft Community Center
Please note that the platform page will load after a while depending on the network environments.
You can also access the page as follows to submit feedback.

You can use a personal account or a Microsoft 365 work or school account to send feedback.
Your understanding is greatly appreciated!
Have a nice day!
Sincerely
Cliff | Microsoft Community Moderator