Good news it worked !
Nothing better than to start by a good old cleaning and battery replacement !

Will continue to play and learn more about XCP-ng and XOA now!

Thank you guys, for the help!

With kind regards.

@Danp, @DustinB ,
I have taken the full machine apart, did a full clean up and cpu repaste.
I also changed the Bios battery. After that the VM is now starting correctly.

I will give another try with XOA Deploy and see how it goes. I would like to double check if I'm reproducing the original issue.

With kind regards.