With the recent Wave 2 Release for Dynamics 365 there has been a slight change to how the header works on a Form, which is known as the High Density Header. With this change, users can add more than four fields to a form header while sacrificing the ability to edit the fields without using a dropdown. I had previously written a blog on this which you can find here. Below is a screenshot of a header that contains more than four fields.
Although this feature has its benefits, as I mentioned before you are unable to edit the fields without using the dropdown. This can be an annoying user experience if your header only contains four fields or less, as it adds an unnecessary click. If you navigate to https://make.powerapps.com/ you will be able to use the Power Apps form editor. Clicking on the header in this new form editor which show the two options below.
The first option controls this new feature, while the second controls the dropdown that is shown when the arrow is clicked in the header. Unticking the second option will make the header fields permanently read only. Unticking the first option will return the header to how it was before this update.
With this, the header will take up the same amount of space as it did pre-update. The fields displayed in the header can also be updated without the dropdown, but the dropdown is still available for overflowing fields.