how to with 2 routerOS?

Hi to everybody, I had previously posted this question but after 10 reads nobody answer, I belive I don’t explain wery well.
I had one mik used for backbone, I use ospf routing, and it’s setup with pppoe server.
With this configuration all works ok, user directly connected on the lan interface authenticate wia radius and navigate.
Now I need to connect another mikrotik not used for backbone but for distribution, the 2 wlan interface set to ap-bridge and the lan on the switch where there is the mikrotik used for backbone.
On this second mikrotik I had set first the ether interface with an address on the same subnet of the one used for backbone, I also change arp to proxy-arp.
I define the same set up like the first but I do not assign wlan ip address because it is assigned via pppoe. I set up radius and other things, I add a route dst-address=x.y.z.h/24 gateway= (ip of the backbone lan).
The problem is that:
the lan users of backbone cannot authenticate (on the two mik there are pppoe server enabled)
the wlan user of the ap cannot authenticate, only if I enable the secret but do not navigate.
It’s so confused but anyone will help me?
thanks in advance.