LbaaS with OpenVPN Access Server

Hello Folks,

need your knowledge please.
I have openstack 12 in place and lbaas configured.
with neutron commands i have create a loadbalancer
as pool member i use openvpn access server.

the goal is.
different instances have its own openvpn access server. To use only one floating to access into the instance I have configured a lbaas and use different ports for each openvpn access server.
eg. Pool1 with port TCP4500, Pool2 with 4501 etc.

The logging or monitor mechanism on the openstack is not so good.
But what I see.
with lbaas-loadbalancer stats lb I see the incoming traffic but no active connections.
on the vpn appliance i checked with tcpdump the traffc and it is comming in and the server is answering but the vpn cannot be established.

Has someone any experience with it?