NativeSelect is empty until page refresh

The first time a particular form is rendered one field of type NativeSelect is always empty (it contains no rows at all), and its
caption is not rendered. When the page is refreshed the NativeSelect has its rows filled and caption displayed.

Debug mode shows no errors.

Other forms on the same page have NativeSelects which are drawn correctly.

The particular form has the NativeSelect as its first field, something which may be unique to the problem.

Has anyone else seen this behaviour?