Double ARP with Hotspot on bridge

I have successfully configured a transparent hotspot, but it is giving me some unexpected results.

The Hostpot is configured on a bridge, and everything is working fine (If the gateway router is another Mikrotik), but as soon as i get the hotspot login page the client’s mac appears twice in the arp table, with 2 different IP addresses.
The DHCP log shows no trace of the second ip address, and it does not appear in the lease table.

If i start Torch, i can see the 2 entries, where all downstream traffic is on 1 ip address, and upstream is on the other.

The problem is that in my setup there is a Cisco ASA as router, and it can’t handle the double ARP entries.

I have attached the configuration, if anyone knows what this issue could be..
config_TPOE_Test - Kopi.rsc (5.05 KB)