BUG(I think) : linux-dtb-current-sunxi64_20.08_arm64.deb Error while loading /var/lib/dpkg/tmp.ci/preinst: Exec format error

Hi, I have downloaded `Armbian_20.05.2_Pine64so_buster_current_5.4.43.img` I have a script that mount the iso, chroot into it and run a big script to generate a flavoured version of armbian. 
First thing the script do is `apt update && apt upgrade`   And I recently started to have the following error:
 

Preparing to unpack .../06-linux-dtb-current-sunxi64_20.08_arm64.deb ...
Error while loading /var/lib/dpkg/tmp.ci/preinst: Exec format error
dpkg: error processing archive /tmp/apt-dpkg-install-xF9W1s/06-linux-dtb-current-sunxi64_20.08_arm64.deb (--unpack):
 new linux-dtb-current-sunxi64 package pre-installation script subprocess returned error exit status 1
Error while loading /var/lib/dpkg/info/linux-dtb-current-sunxi64.postinst: Exec format error
dpkg: error while cleaning up:
 installed linux-dtb-current-sunxi64 package post-installation script subprocess returned error exit status 1

I googled a bit and found this post :
https://askubuntu.com/questions/1001795/unable-to-execute-new-pre-installation-script-var-lib-dpkg-tmp-ci-preinst

It stipulates that perinst file in the package should start with a shebang, I have checked and it's  effectively missing in the package.

Running the `perinst` file strait on the prompt does not trow error.

Am I getting something wrong or I just win the opportunity to fill an official bug report somewhere ?? 

--Fred