There has been talk on the Zwift podcast about ANT+ dropouts and people trying to get to the bottom of it. One reason is a huge increase in the number of people, which then causes your PC to try to render more people at once, and then if you have a pc that isn't very powerful, it drops subroutines to keep up the core processes. ANT+ antennas coming in from USB is pretty low on the PC's list of priorities and it gets dropped.
I noticed my 2015 macbook air (pretty weak pc for zwift) started doing this during busy times at busy intersections, so I switched my trainer from external ANT+ via USB to bluetooth, which is inboard and possibly won't get dropped to save resources as fast. It seems to have fixed it.
Also, close everything else besides Zwift. For example, I usually run first thing in the morning. If I leave a browser window with the local weather open (even minimized in the background) it is refreshing every so often with a ping to the internet to get the latest, which ends up slowing Zwift down. So close stuff like that, email, and anything with ads. They are constantly running against the cpu and also taking up bandwidth. Then Zwift can breathe easier and quit crashing subsystems to keep it's head above water.
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