Hello Fernando,
to be honest the set up is not really clear to me, not because of the topology but because of all the bridges you created.
Once thing I am confident enough is that if you have clients connected to wlan1.N and then you have a bridge configured as { wlan1, eth0, bat0 } this is not going to work as expected.
Traffic sent over wlan1.1 will not be delivered to the bridge and so not delivered to bat0.
You should include wlan1.1 in the bridge itself.
Other than DAT, I expect this to be a general problem.
Cheers,