Atari 800 and Picade joystick

I can’t get the Picade joystick to work with the lr_atari800 emulator. I’ve read the docs and know you need to bind the port (1?) to Atari Joystick but no joy.
I can get it to work if I use an external controller - DS4 over Bluetooth - but want to have the picade joystick working.
I’ve read other posts and see that it’s a tricky issue but nowhere can I see the answer?
Thanks!

And somewhat strangely - the Picade joystick DOES work fine if I have the external controller attached. It won’t work if not?

Has anyone figured out how to map the buttons and joystick on the Picade to the Atari 800? The configuration files don’t appear to have any options and there’s no in-emulator menu.