I’m using ngTagsInput in an AngularJS CMS. ngTagsInput has a ton of great options but does not support a scrollable area in the suggested tags list. Here’s the css to include a scrollable area for suggested tags.

tags-input .autocomplete .suggestion-list {
  width: auto;
  height: 300px;
  overflow-x: auto;
  overflow-y: auto;
  white-space: nowrap; 
}