You can use a static command to create a 1-1 static address mapping with the inside address the same as the address on the DMZ. You are probably using a global command and a nat statement. You can use the static command and map 10.xx.xx.xx to 10.xx.xx.xx from inside to dmz instead.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...