Stepping through jumps to a User Defined Function

[TryToExcel]

When I am stepping through a macro using "F8" I end up jumping to a User Defined Function part way through the stepping process. I then have to step through the function or press "F5". Why does the macro jump to the function and leave the macro and how can it be avoided? When stepping through the macro and I come upon the return value of the function the macro will change the active cell of the worksheet based on the return value of the function.

Danny

[royUK]

If the macro uses the UDF then it would be part of the process of stepping through

[TryToExcel]

Thanks. I saw where the stepping exits the main macro to the UDF so I put a "Breakpoint" where it returns and I use "F5" key on the last step prior to when I exit the main macro so it "bypasses" my seeing the function.