How to update the document type linked to extract?

We have requirement to update the document type linked to Extract in delivery options. Currently when we go to the extract definition and update the system document type, we can update and Save it but after validating and going out of extract when we open the extract again the changes are reverted back to what was present before.

Please guide on how to achieve this?

I have also tried importing the extract from Prod to test env but even in that it does allow changing but once we move out and come back to the extract the changes are missing.