Hi,
I’m having a similar issue with buttons on this page. <p> tags are being added around the <a> or span for buttons, which prevents the width from being styled properly.
I have checked and wpautop is not running on these pages, and I’ve been trying to disable most plugins but struggling to find the culprit. I’ve taken a look through my template files and can’t spot anything there either.
I appreciate that the help other people can offer will be limited as they can’t look at the plugins/template files, but I just wanted to post in case the original poster above had ever found the issue? Or if any others have found any plugin incompatibilities as that might give me somewhere to start.