Duplicate bundle item

We have had some orders where a bundle has had a duplicate item added. e.g. a bundle will have three items and the order page lists four with “(bundled in Bundle Product Name)” on all four items. The extra item seems to be the one that is listed first in the bundle and is appended after the bundle (before other items in the order). The duplicate is both times with quantity 1.

I’m not sure how to debug/reproduce this.

Presuming this is happening in the cart, it should be possible to validate the bundle as the order is created.