ECG app on Apple Watch fails to record

I have Watch 5 running on WatchOS 9. Yesterday, I noticed that the ECG app is not working. When I open the app and put finger on the crown, it appears as if the watch attempts to record ECG but fails to do so. The counter keeps getting reset to 30 seconds and I get message saying 'Hold your hand still'. This is unusual because I have tried more than 8 times since yesterday to record ECG without success. I have never faced this issue in the past. I have tried restarting the watch, cleaning the back of the watch, and even removed dust from below the crown with a piece of paper. None of these worked. Any thoughts about how I can resolve this problem?