Add instance dropdown does not scroll with window, Win 10 Chrome browser

[PerRoine]

Describe the bug
The "Add instance " Dropdown does not scroll with the window you have to zoom out to see alle the alternatives if you are in a stdandard zoom on 1368x768 screen (small laptop)
To Reproduce
Steps to reproduce the behavior:

1. open admin and try to add an instance
2. zoom inn so that the dropdown list fills more than your screen area and try to scroll up and down, the page scrolls but the list is stuck
   Expected behavior
   A clear and concise description of what you expected to happen.

I expect the list to scroll with the end of the page so that all alternatives is available in all zoom levels / Reselutions

Desktop (please complete the following information):

• OS: [win 10]
• Browser [Chrome]
• Version [67.0.3396.87]

[cxselph]

This is also happening in OS X Safari 11.1, Chrome 67.0.3396.87, and Firefox 60.0.2 with current version this morning. I have to zoom out in my browser to see all instances.

On OSX 10.12.6 Sierra

[willosof]

Closed in 004fa45