All seems ok there Dom,
You should be seeing at least some activity on your dump1090 screen using :8080
I suspect the antenna, the ones that come with dongle are not great performers but you can improve things a whole lot with some small changes (cut to correct size) and a tin can to optimise the dongle tv/radio antenna for adsb.
Take a look at first post by member abcd567 below
ads-b-flight-tracking-f21/three-easy-diy-antennas-for-beginners-t20177.html
what happens if you
sudo service piaware stop
./dump1090 --inteactive
anything happening in the terminal window ?