Solved Openvpn.tar creating the right size file

[compsos]

May have found something
If I use the openvpn.tar file from a working phone it loads. Build a new file base on exactly the same data except for the key and crt files and updated auth-data, the openvpn.tar file is 20.5kB but the original working was only 11.8kB. The source files are the same size so that would imply the OS is causing the issue. Have had the same result on Centos7 and Linux Mint machines.
So the phone is rejecting the openvpn.tar file as it is too big.
Now the question of how to build a smaller tar file?
If I create a new tar file from the unchanged set of files the size is 20.5kB and unusable. Could it be a reflection of the cluster size of a newer OS? If so how can we overcome it to satisfy the phone?
Perhaps future firmware may need to accommodate varying size of the tar file.