Edit form submit not working with AddColumn data source

[JTA88]

Hi - if anyone can help me solve this I will be eternally in their debt...

I'm trying to create a library subscriptions app. I was struggling with getting the correct names for my Subscriptions gallery fields, which someone was kind enough to help me with here.

Now that I'm working with a gallery featuring additional columns, though, the detail and edit forms associated with these gallery items are proving problematic.

They both display the "Connect to Data" message, although my data is still showing over the top of them. Going by the solution to this post I have made sure to change the DataSource from my Browse Gallery name to the actual formula for my custom data source with added columns; but the "Connect to Data" message still shows.

This isn't the end of the world, as it's not visible in play mode and the data displays fine. Everything seems to be working, EXCEPT my submit form button. If I click it when creating a new record, nothing happens. If I click it when trying to edit an existing record, I get the "There was a problem saving your changes. The data source may be invalid" error message, as queried here.

I have tried everything I can think of; I've gone through every line of code I've written, I've remade the forms from scratch, I've saved, published, exited, re-entered, you name it. Nothing seems to work.

What's super frustrating is that these forms were working and submitting fine a week ago, so I don't know what's gone wrong. I previously had the idea of linking multiple galleries to the same edit form, and was playing around with that as an option, but soon realised it wasn't necessary for the app and so removed all the extraneous code. That's when it seemed to completely break.

This is the final thing I really need to fix before I demo this thing. Praying someone out there has an answer...

[Drrickryp · Accepted solution]

@JTA88 

You have to maintain consistency between the datasource in the form and the datasource and item property of the forms. In the example on the right, the datasource of the gallery is 

With(
    {
        wcontacts: AddColumns(
            FakeNames,
            "citystate",
            city & ", " & state
        )
    },
    SortByColumns(
        Search(
            wcontacts,
            TextSearchBox2.Text,
            "company_name"
        ),
        "company_name",
        If(
            SortDescending1,
            SortOrder.Descending,
            SortOrder.Ascending
        )
    )
)

The Item property is Lookup(FakeNames, ID=Gallery1.Selected.ID) and the datasource of the form is FakeNames.  It functions perfectly. 

[JTA88]

THANK YOU!!! I owe you a beer 👍