Display of Current Heart Rate on iwatch 3

Heart rate takes to long to display on the watch face when reading. It logs the rate in the health app but it continues to try to read and display. Sometimes it works after about 30 seconds, but mostly it doesn't display at all.

This was working correctly (showing rate after about 5 seconds for launching the app on the watch) about a week ago but all of sudden it stopped. Apple sent me a replacement and the replacement is doing the same thing. It makes me think that something in the health app in my Iphone 7plus is not right but I can't seem to figure it out.

Does anyone have any insight as to why this failure/delay of the heart rate would be happening???