Might be a coincidence (or Zwift fixed it and didn’t tell anyone).
I have had non stop disconnects (“Unpaired”) on my Apple Watch HR monitor. I deleted the Cardiogram HR App from my Apple Watch that was installed on it. Since then, I’ve had zero “unpaired” issues and have been very happy. It still drops from time to time (one second or so) but zero “Unpaired” issues. Worth a shot if you were plagued with this too. Good luck!