Hello Powerapps Dev Team,
The "New" feature "Explicit Column Selection" renders the app unusable with Named Formulas.
The presentation of the error is that it will not load Named Formula data. Of course, that being linked to other items in the app, renders the app unusable.
The temporary fix was to apply the setting "Disable explicit column selection" which restored the app to its proper function.
The error does not appear in the "Edit" development mode of the app, but only in the published client side which is quite unusual. It simply does not load the information from the Named Formulas in the published app, but does load the information properly in the edit mode.