Heart Rate will not collect data while using pool swim in Instinct

I found out the similar question and answer was -

"For using your OHR sensor while using the Swim APP, double check your OHR being set to On for swimming when you go to your Settings > Sensors & Accessories > Wrist Heart Rate menu. The Status show should Auto and when you go down and check While Swimming, it should show On."

It is also OFF in my instinct but the problem is it does not turn on. I tried pressing every key after reached that screen. Please can anyone guide!