We probably all have experienced this issue while zwifting, a sudden drop out of the heart rate monitor. Or even worse a dropout of the trainer itself, and the watts goes to zero no matter how hard your pedaling 🙁
First things first and that’s understanding what type of connections you are using, either Bluetooth or ANT+? But these days your most likely using bluetooth as most devices will support this out of the box, without an extra ANT+ USB dongle.
Understanding the issue
The first thing that you should do is to understand what kind of issue your dealing with. So the most easy thing to do is analyse the zwift log file, depending on the device it should be located in the folder: Documents/Zwift/Log/Log.txt. This log file contains all errors (if there are any) and connection to all the sensors like hrm, trainer etc.
If you upload this file to Zwiftalizer you get a nice overview of the connection quality and any drops or reconnects.