I have a powrlabs HRM and it is my third one. I started having issues about a month ago. It would connect fine, but drop off or regularly show a value of about 1/2 my heart rate. I replaced the battery and same thing. Bought a new on and appears to be the same thing. I have not isolated it to a Zwift problem but wanted to know if anyone else was having the same issues or if this might be something from and update. I use Companion app and an Apple TV to run the Zwift software.
Thank you,
Never heard of it. I would stick to the likes of Garmin, the older ones that detach from the belt are better or use a CooSpo H808S from AliExpress which will be the go too once all my Garmin ones die.
Test it with some other app to see if it works
They have a list: Powr Labs™ Chest Heart Rate Monitor Pairing – PowrLabs
I have a Wahoo arm band. It used to work really well. I found when it started acting up, it was time to charge. Butttt. Lately, maybe since the last update. I have had issues with it not connecting. Dropping out, half way through. Today I did a sprint, and my heartrate said around 90bpm. I moved around on my arm, and wet the sensor. Seemed to come back. I really like my coros HRM when running (treadmill or outside), but if I want to use it for cycling on Zwift (it will connect, then drop connection). So I start a virtual ride on my garmin watch (which connects to the HRM) then I connect my forerunner as the hrm. It works perfectly. Not sure if it’s a Zwift thing. Just the crap I deal with on a daily basis 
It has worked perfectly for 3 years. It started doing this and I bought a new one to see if the old one was goofy after I changed the battery. Now both are doing this. Wondering if there might be some noise that is interrupting the blue tooth signal. It sees it like 1/2 the time. HR displayed is about 1/2 of actual. New battery, connects fine, sensors are wet, tried different straps and results the same with all combinations.