Whoop 5.0 Heart rate sensor feels a bit off.

Hi everyone, I recently bough whoop 4 days back and started doing my weightlifting session. But i don’t know why the hr sensor feels like its not detecting my hear rate accurately after finishing a heavy set the heart rate still shows around 100-120bpm thats it while my earlier apple watch series 7 shows somewhere around 140-160bpm during the same exercise and on the same weight. Im wearing it on the wrist of my left hand 1 finger above the wrist bone and the sensor falls somewhere around 2 fingers above the wrist bone. What should i do any suggestion or tips ? Thanks !