There is not enough information to say.
Is pfSense the OpenVPN client? Or server? Is x.x.x.x an IP address on pfSense, or a remote system?
How is the OpenVPN instance configured (which interface is it using, etc)?
pfSense is the OpenVPN server, x.x.x.x is the WAN address of pfSense.
OpenVPN is configured on the WAN interface.
Since originally starting this thread, I've made configuration changes, probably correcting errors. Now OpenVPN seems to be working correctly and I have not been able to duplicate the condition about which I originally posted.