Custom field as a cart attribute not working in VM 2.9.9a

[moginn]

I have a custom field called "size" and I checked "cart attribute" and "is a list?". The "default" field is set as a "small; medium; large". Well, when the detail of the product is shown, three combobox are displayed instead of one. Please look at the attachment.

[attachment cleanup by admin]

[GJC Web Design]

Easiest is to install the test products data on an install - there you can see how the various custom fields work