Most likely reason is that, for the current values on your current record, that relationship fails to match to any records and thus there are no hockey team names to put into the value list.
The following temporary changes to your layout may help you identify the trouble.
Put a portal to Hockey_Team onto your Hockey_Division layout and select the Team_Name field as the field to show in the portal. This portal should list the same names as appears in your conditional value list. I predict that the portal will be empty.
From here, you'll need to debug why. Make sure that Hockey_Team::_fk_DivisionID is an indexed field. It probably is indexed as you'd get an error message when setting up the value list if it wasn't, but if something you did disabled indexing on it later, this might be the problem.
More likely, one or both of the divisionID fields don't have the right values in order for them to match. Examine the __pk_DivisionID field on your layout by making a copy that's formatted as an edit box or use a watch expression in the data viewer (requires FileMaker advanced) to see it's actual value. Then go to a list or table view of your teams table and compare that to the values in the _fk_DivisionID field to see if there is something in those fields that keeps records from matching as you expected.
Thank You philmodjunk,
Apparently I had created a second record in the Division with the same name but of course, with a different Primary Key ID.
As soon as I deleted the second record it worked perfectly.
Lesson learned: For testing purposes I will show the primary key which would have been so obvious