Cannot change Deflate Method or 'Characteristics' when adding new file to an existing zip

[ZoeESummers]

I have a file that is created from a game. It's a zip file.

When I open that file, all items inside have a 'Method' of Deflate:Maximum, they have no 'Characteristic' and a HostOS of 'FAT'

However when I drag drop in a new file into this .zip, the 'Method' is just 'Deflate' and the 'Characteristic' is marked as HTFS and adds an new Attribute of 'A'

This is causing a problem in that when the game reads this zip file, it cannot see the newly added file(s).

I cannot find anywhere either on import/add or in the Settings to change these values.

Can you solve this by asking the user when dropping the new file(s) in, what Method and Characteristic (if any) you want to use when adding them to the existing zip?

Thanks.