Photo size dropdown missing when editing multiple/repeater


I have a created a collection of custom BB Modules. Some of them have a repeating/“multiple” field where users can add items (e.g. carousel slides). Most of these include a photo field on the form nested inside the repeater.

When a new item is created inside the repeater, it is possible to add an image to the photo field and select the required size from a drop-down field (Thumbnail, Medium, Original, etc), this works fine.

I’ve noticed a problem that when the admin returns to edit the page again in future, this size drop-down is missing, I can see that it is hidden with a ‘fl-photo-no-attachment’ class, and the drop-down only contains one size. The only way to change the size is to remove the file and re-associate it again, which isn’t ideal.

Is this a known issue? Is there a workaround at all?