Comment 4 for bug 1888033

It might be helpful to take a closer look to see exactly what has changed.

For example, do a binary comparison:
$ cmp -bl old/efi.img new/efi/img

Or loop mount the img files and examine the contents:
$ mkdir mntold
$ mkdir mntnew
$ sudo mount -o loop old/efi.img mntold
$ sudo mount -o loop new/efi.img mntnew

mount may want to make its own changes so make sure the img files are writable.