Bri
To confirm your comment, there have been plenty of aircraft tracking all night which you should be seeing on the map - I've been on since around 17:00 BST and it's been very very busy this evening -all sorts of traffic around
One thought -are you running off a desktop or laptop? My laptop has been running in a very peculiar way this afternoon when it was very very hot, which was appearing to slow down the speed of some functionality on Radarbox - could it be your hardware?
Rich