Hi Rob. I suppose it's possible arm is having a refresh issue but can't say there's a known bug around that. To double check try running tor-prompt and giving it 'GETINFO circuit-status'...
https://stem.torproject.org/tutorials/down_the_rabbit_hole.html
This is the command arm uses to get the circuit information.
ARM version 1.4.5 seems to be the latest version. I checked out NYX but failed to get it running (Unable to load nyx's internal configurations: [Errno 21] Is a directory: '/home/rob/src/nyx/nyx/settings')
Interesting! How did you attempt to run it? Nyx is under active development so quite possible I buggered something up but can't say I've seen this one. Please provide the exact commands you ran - for instance...
% git clone http://dccbbv6cooddgcrq.onion/nyx.git % cd nyx % ./run_nyx