Apple Watch stops tracking heart rate during Apple Fitness+ workouts

My Apple Watch Series 7 suddenly stopped tracking heart rate on Tuesday when I started a fitness+ workout. I’ve been going through other discussions to find a solution but I’ve found no luck. My watch also randomly locks itself and I have to unlock it a couple times a day even though it’s on my wrist.

So far I have closed all apps, turned off both my phone and Apple Watch, I then unpaired my watch.

Now my watch only tracks up until I start a workout and then it will stop working afterwards. I have been wearing my watch the exact same way for nearly 3 years so I know it doesn’t have anything to do with tightness.

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Original Title: apple watch stops tracking heart rate as soon as I start an apple fitness workout