@leybal after investigation, we found the reason. Hide the workbook and close Excel. Reopen the Excel and unhide the workbook -> in this step, Custom Function (CF) is processing before "unhide" action ...

Composite functions are made when the output from one function is used as the input of another function. The names of the functions are written next to each other, with the function that is used first ...

This block continues with more algebra including algebraic fractions, using and transposing formulae, some functions and remembering the equation of a straight line, its gradient and intercept. You ...