Hi,
I'm observing two trends here: people that tried everything to no avail, and people that tried random things and that ended up working. The last procedure I saw just makes no sense: first requires two computers, the second computer seems not to have no Fitbit application installed but the procedure suggests to add the device on it and that ends up working, then try on a phone and it works. It looks like we don't have enough information to solve this issue and we are thus forced to try things blindly. This is the sad result of closed source software and protocols without any diagnostic logging exposed to users. I'm pretty sure Fitbit developers can get diagnostic logging, using undocumented options or even worse, debug builds nobody else has access to. There is little we can do to solve this, as there is a common misunderstanding that opening protocols and improving diagnostic logging will violate IP.
First test fully with one device at a time, making sure the Fitbit is not paired to any other device. If you can turn off Bluetooth on all your devices except the one you are testing the Fitbit on, it is better. Make sure Bluetooth on that tested device is working properly. If you have another Bluetooth device such as a speaker or headphone, try if that still works. If the phone or computer has faulty Bluetooth, there is absolutely no chance the Fitbit will synchronize properly.
Then try to add a new device to your account, select your Versa and follow the steps. If a device already exists, it will offer to replace it and say "yes". If the setup fails, what happens? It can refuse to connect with an error or wait forever to synchronize or install firmware. Long installation is likely caused by the exclusive use of Bluetooth; you need to use wi-fi to setup the Fitbit, but unfortunately, you still need Bluetooth for the Fitbit application to tell the watch about the wi-fi connection.
In my case, my Fitbit stopped working with my phone (error when synchronizing), I cannot figure out why. After a factory reset, I got this insane "data not cleared" message and any attempt to add the device again failed. It appeared non-working in the Fitbit Windows application, but in fact, it was connecting and displaying (on the app) an indication leading me to think it was trying to connect without success. I had to click on the arrow at the bottom of the screen to go to next step, then was asked to setup the wi-fi and the firmware installation went on. That removed the "data not cleared" message and allowed me to use the watch again. But if I try to synchronize with my Android phone, it fails, same error as before this investigation. Trying to add the device again (on my phone) just fails after a few second with a message listing steps to try fix it (steps that never work). If I don't turn off the Bluetooth on my Android phone, synchronization with my Windows laptop fails, even though I unpaired the Fitbit from my phone. Moreover, when I tried with my desktop computer with a Bluetooth dongle, that failed as well to connect; that works only with my laptop offering onboard Bluetooth.
Bottom line, it seems the Fitbit has limited Bluetooth and maybe even wi-fi compatibility with other devices. Some people got luck after returning the watch and getting a replacement one, so maybe some watches work better than others. I agree, that's very irritating and a real waste of time and energy.
