I have made sure nothing is running in the background.
The problem is more than just a low frame rate - the program ‘hangs’ for a second or two about every 3~4 seconds. My USB connection to the computrainer has lights that blinks when communication is occuring. With a normally running Zwift session, the blinks are rapid and continuous. Now, on OSX Mojave, the blinking pauses along with the observed program hangs.
I’ve made sure the correct USB drivers are installed/active. Right now I’m just putting this down to Mojave/USB wierdness. At least I have another computer to use (an older macbook pro), wich is not as good as the one I installed Mojave on, but it’s workable.
If I load up Zwift and choose to just watch (no connections to sensors), Zwift behaves with a normal frame rate, so I know it has something to do with the USB connections.