Wierd issue with VBA driven chart updates - works for some not others

[dawatcher]

Hi All and Happy New Year,

I have a bit of a weird issue I can't quite understand.

Using some code found online (not this site) I have tried to create a dynamically updating chart from a combo box selection.
The weird thing is, for 2 of the 6 selections, I get the expected chart - for the other 4 the charts are incomplete (Only charts one col out of 3 for example).
Please see the attached sample workbook for a clearer picture. Why is the same code working for some cases but not all?

Thank you for your assistance.