Since you are collecting your data using a Flow (now re-branded as Microsoft "Power Automate"), it will take anywhere from a few seconds to even a few minutes to run, so when your form becomes visible there won't be data in the collection until the Flow is complete. I would suggest in your "On Start" of your App to initially create this Collection with just one record of dummy data as a placeholder so that it is available immediately at the "On Visible" of this screen.
Check out this article about Power Automate (Flow) performance.
One thing to notice is that EditForm doesn't support the Collection as data source.
So if you want it, you have to create each component manually. Use label to show the column name , use Textinput box to enter the value, and use combo box to choose selection, and then group all component together as a whole.