Client MAC over the network with Hotspot

Hello
I have the network configuration shown in the image below.

But I’m having the following problem.
With a smartphone, I connect in a mikrotik RB951 through the wireless network, this mikrotik is working only as Access Point. In the Routerboard there is a Hotspot service, this service sends to my server the MAC of the User to do its authentication. The problem occurs between the communication between the RB951 and the Routerboard, the MAC that I am receiving in the Hotspot service, being the MAC of the ETH1 port of the RB951 instead of the Smartphone MAC. What should I change in RB951 so that the Client MAC is sent to the Hotspot service?
Thank you in advance!

Looks like you’ve set up your 951 as a router, not as a bridged IP.
-Chris