Power App: Edit Form combobox from Dataverse - referencing other columns

Question

I have an edit form which is populated from a gallery. The forms and gallery use different dataverse tables as data source so I'm using a common ID in both tables to link them and use a variable in the OnSelect property of the selected gallery item.

In the edit form are comboboxes which use lookup columns in dataverse.

Currently the values seem to be those of the lookup column i.e. UINs.

How do I go about getting values from another column in that dataverse table instead of the parent column which its currently returning please?

Here's the structure of the Items property of a combobox which is returning the UIN instead of the desired text from a second dataverse column:

Sort(Choices([dataverseTable].lookupColumn),secondDataverseColumn,SortOrder.Ascending)

I've changed the primary text field of the combobox from the UIN which does result in the combobox dropdown values being text but the box is now empty and without value relating to the selected gallery item. The search text seems to have changed and the original ID option has disappeared.

Thanks