Access denied error listing VirtualBox vms

I try to run a Job in Jenkins that executes a Python script that lists and exports my VirtualBox virtual machines, using the command-line tool vboxmanage, into a Windows machine. So, I created a Jenkins agent, and installed it as Windows service and changed the service logon credentials to be my personal account. I checked that the service runs with my account in the services list.

But, when the job is run by the agent, it prints out:

VBoxManage.exe: error: Failed to create the VirtualBox object! VBoxManage.exe: error: The object is not ready VBoxManage.exe: error: Details: code E_ACCESSDENIED (0x80070005), component VirtualBoxClientWrap, interface IVirtualBoxClient comando: "C:\Program Files\Oracle\VirtualBox\vboxmanage" list vms

The Python script works well if I run it manually into a CMD window. Also, I used the function os.getlogin() to print out the Windows user that is running the script, and it is correctly my personal user which owns several virtual machines.

I can't guess why I cannot access nor interact with my virtual machines. Any help would be very welcome.