OVPN + PIHOLE - client ip mystery

[firewall]

Hi All,
At some point I had everything setup properly such that DNS for clients connected to OpenVPN Server on the OPN machine was forwarded to an internal PIHOLE machine, and the OpenVPN client IP/host resolved properly.  Now, and although DNS is working properly, all queries show up in PIHOLE logs as having originated from the OPN IP.

So I understand this is specific to a 3rd-party technology (PIHOLE), however there must have been something I changed on the OPN side to cause the masking of IP.  The problem no doubt has to do with the fact the OVPN clients reside on a different subnet (by design...I'm not even sure you can configure it to be on the same as LAN) but it worked once so I'm trying to get there again.

Any insight into which settings I need to align to expose the OVPN client IP(s)?

Thanks!