Cannot get search with geocode to return anything other than an empty array


I’m new to the twiitter REST api but I have managed to get quite a few things to work

If I do a search like this then I get results back (with the appropriate verified credentials obviously)

However if I include a geocode I always get an empty status array back

I’ve tried passing the comma unencoded in the geocode and I then just get a status 401 error. I also tied passing it as %2C as opposed to %252C and that gave error 401 too

I’ve tried quite a few combinations but just can’t get anything to work

What am I missing ? do I need to turn on some service/switch or something ?