so it seems that without any config, the traffic passes from wlan1 to wlan0’s network flawlessly; but traffic from wlan0 network stops at the Android device, even with iptables -P FORWARD ACCEPT, so I’m clueless on what to do next

how could I set up NAT like this ? thanks

ip r

default via 192.168.15.1 dev enp3s0 proto dhcp src 192.168.15.32 metric 100
192.168.15.0/24 dev enp3s0 proto kernel scope link src 192.168.15.32 metric 100
192.168.38.0/24 via 192.168.15.21 dev enp3s0    

That’d be over 1TB with zram on