App: Check if by any chance your phone's Bluetooth shows the Sense as a connected device. If so, please unpair/remove it. Remove the Sense from your Fitbit account and your phone's Bluetooth settings. Force quit the Fitbit app.
FitBit Sense 2 Device: Hold the side button until the logo reappears then after you see the FitBit Logo with a Circle around it release (it takes more like 20 seconds), a further 35-second pause until the logo goes out when your "Sense" should be back to normal.
*Note if you didn't hold down the button long enough you would see a red X in the end that just shows you restarted it not a Hard Factor Reset.
