Thank you very much! It works now on Windows 10 by using “OpenVPN Community Client” (v.2.5.7 for me).
The setup is a different but the .p12 file is read from the openvpn config dir.
The OpenVPN Connection is hidden at launch, so I’ve found a good tutorial here:
https://community.openvpn.net/openvpn/wiki/OpenVPN-GUI-New
cheers