To share url inside a iframe doesn't show the form in android mobile mode. It appears a green form with the Microsoft Forms logo and a link to the click and redirect to the form url in a new page, which works fine directly withouth iframe. In desktop mode on android works fine because it shows the form created. In faq questions says that works on any mobile (last versions) which is not true! On iphone works fine in mobile and desktop modes.
Please finish the product to run properly on any mobile operative system.
Jakob Neua Nørgaard commented
We also have this problem making it impossible to use the forms system as our users just get a fill the form instead of the form.