Multiple WAN IP - OpenVPN server not working

[aksio]

OPNsense 18.7.4
1 WAN static, 1 LAN static.
Setup OpenVPN server (from wiki manual) - working fine...
Need 3 WAN IP address, add 2 via "Firewall:VirtualIP:Setting", mode "IP Alias" - ok.
After this, OpenVPN clients cannot connect to server:
In OpenVPN server log serial messages: "openvpn[...] <....> write UDPv4: Permission denied (code=13)"
On client side server address not available, connection not possible.

How the solution was tried:
In "Firewall:Rules:WAN:rule for OpenVPN change "Destination" from "WAN address" to single IP (main WAN IP) - did not help.

After remove 2 WAN IP address (IP alias) and restart OpenVPN server, it all worked.

How to add 2 WAN IP for the OpenVPN server to work?