Thank you. Unfortunately, that machine is in datacenter so dont have physical usb access.
Nevertheless, I found a way to do the conversion. Seems as XenConvert 2.3.1 is capable of doing it, however, its only that version that does it, the rest are all different.
Therefore, issue resolved for conversion, but i'm still wondering if im the only one that had that issue or is it quite common given the system version I have to xcp and the center.