Hi there!
Is it ok that if there is iframe tag inside Custom Floating HTML Prompt
it opens iframe link in new browser window without showing any floating prompt?
Is it a bug? Why it opens browser instead of prompt window?
Shouldn't HTML Prompt window with embedded page have been shown instead?
Or is it normal behavior?
I can confirm the behavior. Take a look at Website Popups Using Automator in the Macro Library here. I think that will get you where you want to go.