Connected to Garmin Dual HRM but no picking up signal

Using a Garmin Dual HRM (over bluetooth) the Zwift App connects but does not pick up a heart beat. I have checked and (i) I am still alive (ie my heart is beating) and (ii) my Garmin Edge picks up the heart beat (ie it is not an issue with the HRM itself)

I have deleted and reinstalled the App, but same issue.

Any thoughts?

Bluetooth can only connect to one device at a time, so be sure it is not still connected to your Edge via BT (which is likely isn’t, as it would more likely connect to the Edge via ANT+). Also be sure that the Dual is not connected to your phone, or any other device. It’s also possible that you may need to wet the contacts of the chest strap to get a solid signal from the transmitter.

Nigel, thanks for this. I have read that Bluetooth CAN connect to more than one device, indeed it connects to the Wahoo trainer and the independent cadence sensor and those feed through into the Zwift App (on my phone) without issue. In the Bluetooth settings in the phone (and on the face of the Zwift App) it is “connected” but not picking up a “signal”

If you see your HRM in the BT connections of the phone itself, you’ll need to ‘forget’ the device. The HRM should be connected only through the Zwift app directly. As for the connecting to more than one device situation, it sounds like you are talking about multiple BT transmitting devices (trainer, cadence sensor) being connected to a single receiving device (Zwift). This is fine. It’s that, generally speaking, a BT transmitting device (like the trainer) can’t connect to more than one receiving device at a time. So, for example, you would not be able to connect to Zwift AND the trainer app at the same time using BT.

Went through this problem last days. Tried to change HRM batteries, disconnect/connect it in Zwift : no change.
So I remembered I was prompted to update my HRM firmware on my Garmin bike computer a few weeks ago, and supposed the pilot file needed to be updated also on my PC.
I’ve just unpaired HRM from my PC (Bluetooth parameters), and paired it back : works fine back !