Pop-up display issue with Figma Make

When I ask Figma Make for pop-ups, I am never able to change the width of the modal that Figma Make offers me. I regularly want to increase the width of my modal, but after many different attempts (sending a mock-up from Design, clear explanation, etc.), Figma Make tells me that the change has been made, but when I test it, no change has been applied. If you have any advice on how to make the right prompt that allows Make to make the expected change, I'm all ears.