What is your device model? Perhaps this could be an app you've recently installed or this must be representing minimized notifications. Btw, your phone is Pixel 5 phone, at the top center, you can see a white dot when your proximity sensor is on
So, you're seeing a white dot near, but not in, the notification bar? IN the notification bar would indicate you have more notifications than would show in the space provided and pulling down the 'shade' would reveal all notifications. If it's NEAR the bar and not showing on a screenshot (is this what you meant by "taking an app"?) then it's likely a hardware issue.
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