In the Cube Base documentation it notes that:
"In Cube Base, the decimal point character is always set to "." regardless of the computer's local language settings for numeric format."
However, we noticed that if your local system settings are to use a comma (",") symbol then Cube matrices show as using that symbol. Whether it is just the visual representation of numbers is uncertain, but we experienced errors with calculations of decimal values until we set our local number settings in Windows to the "." notation.
So maybe it's possible that some elements of Cube are always fixed to "." and others are not. So possibly this is a bug in Cube.