Are you connected to the Pisound WiFi hotspot on your laptop? Are any of the examples on https://hexler.net/docs/touchosc-setup-other helpful?
One way to see whether there’s any data incoming at all is to:
sudo apt-get install liblo-tools
sudo killall touchosc2midi # This is in order to free up the 12101 port
oscdump 12101 # This will print the incoming data
When changing controls on a TouchOSC client, you should see output like:
/midi m MIDI [0x00 0x43 0x06 0xb0]
/midi m MIDI [0x00 0x42 0x06 0xb0]