Hello! So I just had this problem a few minutes ago and I tried resetting my phone, the app, making sure everything was up to date and my Fitbit still wouldn’t connect. I ended going to my devices, and disconnecting from the charge 2 device, (you’ll be able to find this by clicking the device icon and scrolling and ok the way to the bottom and it should be in red), i have no idea if it removes all of your data because I got Thisbe Fitbit a as a hand-me-down from my sister yesterday so I didn’t have nay do data deleted in the first place. Anyways, once I disconnected from the device, I just reconnected by doing the pin, etc and it worked! I hope this helps! I’m sorry i am new to this 😕