This was happening on several sites. So I copied the original CSS for each theme for the “input” and “focus” for example:
input[type=text] {
background: #eee;
border: solid 1px #ccc;
padding: 6px 10px;
border-radius: 5px;
-webkit-appearance: none;
}
input[type=text]:focus {
outline: none;
background: #fff;
}
Pasted it into a child theme CSS file (or the theme’s custom CSS field in the Admin area) and changed “text” to “email” eg:
input[type=email] {
background: #eee;
border: solid 1px #ccc;
padding: 6px 10px;
border-radius: 5px;
-webkit-appearance: none;
max-width: 240px;
}
input[type=email]:focus {
outline: none;
background: #fff;
}
I also found I had to add a max-width attribute.
Thanks to everyone who has helped with this – really appreciate pointing me in the right direction.