I just found that I could not use the Default Elevation value coming from an out-of-the-box family template by Autodesk because the translation contains a hyphen. Default Elevation became Vorgabe-Ansicht in German. Sadly the formula routine reads this as Vorgabe minus Ansicht and complains that formulas are case senstive despite me having copied the value via the clipboard. This may be an error in just the German localization but you never know. The space between Default and Elevation works fine. As a work-around you can revert to using templates from the original localization.
Found this in Revit 2022.