When I was using a Sheet Modal, I found the backdrop opacity is changing dynamically when I dragged the sheet window.
May I disable the change and fix the opacity?
https://ionicframework.com/docs/api/datetime#sheet-modal
I think the only way to edit the opacity to be set the same no matter what height the modal is opened, is by editing the css in the shadow dom. which it may not be so simple.
you can try this by inspecting the element and drilling down through the elements until you find the correct on. And also use the provided CSS Shadow parts as well to help you.