I tried on an iPhone 11, chrome browser, and that looks all right as well: https://i.imgur.com/xy8Obe3.png
I honestly don’t know what the cause is, maybe a browser plugin of some sort? But since it is a chrome browser, it should show up on an android device, I tried that too, but that worked fine as well.
From the screenshots it looks to me as if there was a bottom margin on the container element. Maybe try this custom CSS:
.proinput {
margin-bottom: 0 !important;
}But I am only guessing here.