Can't delete a voucher in pre-edit error with invalid supplier ID

We need to delete a voucher from the pre-edit error page with an invalid supplier ID (user uploaded with a special character). It is a part of a control group.

We try to correct the supplier ID and select delete. We then get combo edit error. We try to go 'home' and the page asks us to save. We go to the page, click save and go out.

We go back in, and the changes did NOT save.

We try to do the same but BUILD the voucher. We get the same combo edit error and try to save. None of the page changes save. It just keeps looping.