I’m having the same problem. I work on several sites but this only happens on the site which has Shield installed.
Thanks for the tip on enabling the Chrome Flag, which helps but this is only a workaround.
In the Support bar at the top of this page there is a Search Box. When I click in it, a dropdown appears containing a list of the last items I entered into any site Search box.
In the www.remarpro.com Media Library page for the site that has Shield Installed, whenever I click in the Search Box a drop down appears containing my account Username and (starred) Password.
In www.remarpro.com Media Library pages for sites that DON’T have Shield Installed, the drop down contains my previous search items for the site.
Why does Chrome think this box is an account form rather than a search form when Shield is installed?