Dropdown menu is not opened when clicking the 'Add..' button

Steps to Reproduce:

1. Log into https://bugfest-juniper.folio.ebsco.com/ as abreaux/admin
2. Go to Settings/Data import/Field mapping profiles
3. Create a new Field mapping profile by going to Actions/New Field mapping profile
4. Name the profile. Then click Holdings.
5. Statistical codes: Action = Add these to existing
6. Then click the Add statistical code button.

Expected Results: Dropdown menu is opened

Actual Results: Displayed 'One or more values must be added before the profile can be saved'

Workaround: Click the Add... button again, and a blank field is added

Additional Information: The same result for Former holdings, Holdings statements, Holdings statements for supplement, Holdings statements for indexes, Holdings notes, Electronic access, Receiving history