Fixed/Solved.
Was a series of comedy of errors.
Had to use a console on FreeBSD server, a console on pfsense, and web access to pfsense.
in pfsense shut-off DHCP server
while there also removed static DHCP to 192.168.34.50 with bogus MAC to act as a placeholder.
This was first error. ARP picked up address and showed in ARP table, but obviously it was linked to the wrong MAC address.
cleaned out the ARP cache or reboot on pfsense
arp -a on FreeBSD shows pfsense gateway
ping to pfsense works
arp on pfsense now shows 192.168.34.50 mapped to correct MAC address !!
ping to FreeBSD still not working ?
8.) FreeBSD firewall rule drops (blocks) packets instead of reject. Hence no ping. Duh! Sort of error #2 (mental error?)
Adjust firewall rules for testing. Reset.
Ok, now what about ssh into FreeBSd from pfsense console? Nope - reject. So its getting a response of sorts.
Error #3 - FreeBSD ssh config was set to only listen on old address of server, not 192.168.34.50. Fixed.
Now have ssh access from pfsense console to FreeBSd server.
Now what about original endpoint - WAN access to webserver 192.168.34.51? Yup.
Thanks for pointing to arp to help trouble-shoot this.
Peter