@Brad_Olwin As I said in my original post this wasn’t the issue.
This issue fixed itself and I am now able to see zonesense data on the watch and in the app, and I am not sure but believe one of the 2 following things fixed it:
HRM 200 version updated to 5.40
Looking at the HRM 200 manual (Manual) I realized the device have 2 connection types: secure and open. Secure is when the device blinks green twice and open when it blinks green three times. I am not sure what was the connection type when I originally tried to make it work, but when trying again after opening this thread I made sure to use the open connection state.
My hypothesis is that one of the two fixed my issue.
Leaving this for future reference and future google searches, as when I searched this I didn’t find anything related.