Looping "To start, download the Fitbit app" message - one possible cause?

[Tonecontroller]

Around 10/11 November, after 5 months of proper behaviour, my Sense suddenly refused to take ECGs.
I went through the obvious moves of restarting the Sense, restarting Bluetooth on my phone (Moto G7Power), reloading the app, removing and re-attaching the Sense to the app.
Nothing worked.
I decided to factory-reset the Sense, and this resulted in it getting into a “To start, download the Fitbit app” scrolling multilingual message loop, as long as the charge cable was connected. Charge was shown as 100% at this time.
If I disconnected the charge cable, and tried to restart, I got the Red Cross of Death.

(I logged a support call with FitBit at this point, but only got as far as an insistence that I should charge the Sense and try again...definition of insanity)

I reloaded the app, which detected the Sense, so went through the process of attaching it. This went OK up to getting a pairing code on the Sense, which then displayed a Check when entered on the app. However, the app would then not allow me to continue setup by detecting WiFi, nor if I entered WiFi details manually.
I therefore accepted the Bluetooth option, and the setup continued as far as attempting to download setup files. The progress message stayed stubbornly at 0% and I eventually gave up.

Being on holiday then, I abandoned any further attempts at resurrection for the moment, as I was wasting valuable poolside drinking time.

On returning home, I tried the whole setup process again, but still got no response to the WiFi seeking, and the BT approach again stopped in the same place. I started researching cheap substitute smartwatches, on the basis that I could afford four of them for the price of a Sense, and, while checking the specifications, noticed that they all seemed to operate BT 5.0.
I checked the Sense spec, and found the same. I checked my phone – BT4.2...

As mentioned, the Sense had operated happily for 5 months. So this mismatch could not possible be the problem. Could it?​

I deleted the Sense from the phone app, deleted the app, downloaded it on to my Android tablet which has BT5.0.

As if by magic, setup worked fine, found the WiFi automatically, and completed without problems.

So what happened around November 10th to cause the initial ECG issue, and somehow make the BT version mismatch a critical problem?

(I have not been brave enough to attempt re-attaching the Sense to my phone. I don't use the Sense as a comms device or music controller, and have not yet had my phone surgically attached like a lot of people.)

[Guy_]

Hi @Tonecontroller - thanks for the details and good you were able to get it sorted.

Just in case, there can be Bluetooth issues with the phone that persist which may be remedied simply by restarting the phone and/or removing the Bluetooth entries from the phone (which will get remade as part of the setup process).

The watch only supports 2.4 GHz WiFi but also requires a good Bluetooth to make the setup.

[Tonecontroller]

Hi Guy

Are you saying I should have blamed the phone rather than the Sense? The only thing that may be relevant there is that I had flown to the holiday and my phone was either switched off or in flight mode for about 20 hours, so I am not sure what a further restart would have achieved, but I maybe went nuke too early, and the hard reset then screwed everything

The reason I documented this was that (1) a lot of people report the watches going into this type of loop after previously working fine, and I have seen no previous mention of the possibility that BT version incompatibility was considered and (2) if others have encountered similar problems at or around the same date, we may be looking for an app or firmware update as the trigger.

On your last point, when I initially set the Sense up in July, I did not use WiFi, and it configured just fine without it, and worked up until November. The phone itself is stable - I don't think the Moto g7 is likely to be getting any updates - but obviously I can't speak for the Fitbit app.

[Guy_]

@Tonecontroller  - yes a good troubleshooting can save a lot of work and avoid making a simple situation worse.

The watch and phone can sometimes have problems communicating, like when a phone call gets cut-off, it's not necessarily the other person who broke the connection, it can be your own phone.

And having the phone off or in flight mode for any length of time can cause reconnection issues.

So first steps is to ensure both are working optimally by refreshing them with a restart.

When you get the post factory reset multilingual display it means it worked! and a setup is then required. This is normal and different to getting stuck with only the Fitbit logo.

[Tonecontroller]

...except that after the multilingual display appeared, setup failed in this case, and I assume that was because BT failed to connect in a way that would allow the Sense to get its update from the phone.
As I said, the pairing request appeared to succeed, but the data transfer then didn't happen.
Seems really peculiar that the app could neither find WiFi nor communicate on BT even when (apparently) paired.
Lets see if anyone else finds the same thing works for them. I'm just glad that I only use my Sense as a health monitor, not a comms device, so linking it to my tablet isn't a problem.

[mgalwin]

Same problem. What can we do..

[Tonecontroller]

First step is, I think, to check if you have the same issue. Have a look at the description of how the problem presents, specifically regarding where the setup process fails after BT pairing.

If you have the Fitbit app loaded on a device running an earlier Bluetooth version than 5.0, you may have the same problem as I did. At that stage, you need to delete the Sense from the app, disconnect it from the device's Bluetooth, and try to set it all up again on a device that you know has BT 5.0 (or later).

That may succeed in unblocking the loop, and the Sense should then update after it gets the connection to the app, rather than sitting at 0% forever.

After that, I don't know if it would be safe to attempt to delete the Sense from the new device and try try to reconnect it to the one it was originally attached to, or if this might just get it stuck again. I have not been brave enough to try.

My phone is a Moto G7 Power, maybe 3 years old, but still on BT4. 2

[mgalwin]

Not working on BT 5.0 version.