I have a couple of single user picker fields that filter using a group in Jira. When I try to use to use this field in a "Request Form" in Jira Service Management, it does not filter. However, when I use the same field in a "Create New Issue" form it does work.
Here is a screen shot of my fields:

Here is how the field looks using the "request form". As you can see, when I enter "col" I get quite a few names come back. The only name that should appear is "Colleen Gotling".

When I use the create new issue, I do the same thing and only get back the one name that is expected.

Any idea what I might be missing?