#NAME? error for =IMAGE() in Spreadsheet.CellFormula

[RichardJ-iWG]

I generate an XLSX spreadsheet with formula cells that contain =IMAGE("some_url"). When I open the files in Excel each cell shows the #NAME? error until I manually edit the cell. I understand that Excel isn't recognizing the content of the cell as a formula. There are only FormulaType enumerations for String and Number, not Image, and regardless of what I set this to, or if I set CalculateCell to True, or if I set the workbooks CalculationProperties.ForceFullCalculation to true, Excel still doesn't recognize the cell as a formula. I'd appreciate any guidance from the community!