proxy-arp and /32 routes

Hello list, this is my first topic.
I’m having a problem on a RB433 with routeros v3.11
I have the following topology:

PC –– RB433 –– ISPRouter ----- Internet

The ISProuter has a public /29 network on his eth. I want to assign one of those public IPs to the PC.
The RB433 is working as router.
I create a /32 route in the RB433 pointig to the wlan interface and enable proxy-arp on the eth1 interface.
When the ISPRouter wants to route a packet to the IP, he sends an arp-request. The RB433 does NOT proxy that arp!
I made several sniffs on the eth1 and wl1, where I can see the arp-request on the eth1 without response, and no arp-request on wlan1.

Am I asking too much to proxy-arp? isn´t that what is supposed to do? Or am I incorrect?

Salutti.

Edit: here is the topology in graphic format: