SSL VPN with internal CA - root,intermediate and clientCA

Hi all,

I am trying to migrate RAS SSL openvpn from an existing setup to sophos UTM 9 and I am struggeling with sophos certificate management.

The existing openvpn setup works well and from a certificate point of view looks like the following:

rootCA -> InfrastructureCA -> openvpnserver_cert (existing opnvpn and cert imported to sohpos)
rootCA -> remoteaccessCA -> clientXY (all client related certs)

I have successfully imported a webadmin certificate issued by the InfrastructureCA and that works like a charm.
Now, I am trying to import the openvpnserver_cert to be used for connecting openvpn clients, while I can import the cert in p12 format, I cannot select the certificate in the SSL VPN drop-down box? The certificate is available everywhere else  (cisco VPN, HTML5 VPN) just not SSL VPN.


Is there any specific requirement for the SSL VPN setup that I am missing?
Many thanks for any pointers.

Cheers