Unable to select a supplier from the supplier LOV when creating a purchase order in redwood

We have Redwood PO's enabled in 3 of our dev environments and have the application behaving as expected.

We have setup redwood purchasing in another environment and after running all ESS jobs, configuring a custom role for access, enabling all required profile options etc., we've run into an issue where many users are unable to select a supplier from the supplier LOV dropdown. Those users who are able to select the Supplier are then unable to select a Bill-to Location as expected. Those lists are not responding when typing the first 3 letter of a known supplier, nor does clicking on the dropdown arrow.