Cannot tabulate past selectize dropdown

This was my experience with keyboard access to forms:

1. I tabulate through form controls to fill them in.
1. I reach a selectize.
1. The dropdown appears.
1. I tabulate to move to the next control.
1. The dropdown closes with the focus on it.
1. I tabulate to move to the next control.
1. The dropdown appears.
1. go to step 3 and loop.

I think dropdowns are usually activated with Space, closed without change with Esc and closed with change with Enter.