To fix any bluetooth issue, please refer to this topic:
viewtopic.php?f=191&t=333190&start=100

Summing up:
0) Consider updating your device to the latest firmware and performing a factory reset after that

1) Go to "Settings" -> "Background task clear"  and whitelist all your 3rd party apps wich need bluetooth to transfer data (i.e. samsung gear app, veryfit app and so on..). By doing that, they will be allowed to run in background even if the smartphone is in deep sleep state.

2) Go to "Settings" -> "Battery" -> "3 dots" in the upper right corner -> "Battery optimization" -> select "All apps" from the dropdown menu  and disable battery optimization for every bluetooth service app, as
- Bluetooth MIDI service
- BT Tool
- Bluetooth sharing

and for every app needing to use bluetooth to transmit data, as
- Phone
- Phone services
- Call management
- Phone/Messaging storage
- your 3rd party music player
- other telephone dialer apps
- fitness band apps and so on

3) Only if the previous steps doesn't solve your issue, also
- Go to "Settings" -> "Battery" and disable "Standby intelligent power saving"
- Go to "Settings" -> "Duraspeed" and and disable it.

4) Only if, again, the previous steps still don't solve your issue, also go to "Settings" -> "Battery" and set your device into "High performance mode"

Please follow these steps carefully

nonobike wrote:

Hello. 
I want to connect my Garmin Fenix 5 to the BV8000 pro in bluetooth. 
the syncronization worked once ... now it is connected in bluetooth but impossible to syncronized the application. 
Have you ever had trouble with blue equipment? 

Thank you for your help

Fenix 5 is older tech and may have compatibility issues with Android 7 and 8 onwards (Google introduced new security protocols in 7x after discovering older connections could be used to hack into phones…)
 
https://www.google.com/search?q=garmin+fenix+5+nougat&ie=utf-8&oe=utf-8&client=firefox-b

blackview_admin wrote:

To fix any bluetooth issue, please refer to this topic:
viewtopic.php?f=191&t=333190&start=100

Summing up:
0) Consider updating your device to the latest firmware and performing a factory reset after that

1) Go to "Settings" -> "Background task clear"  and whitelist all your 3rd party apps wich need bluetooth to transfer data (i.e. samsung gear app, veryfit app and so on..). By doing that, they will be allowed to run in background even if the smartphone is in deep sleep state.

2) Go to "Settings" -> "Battery" -> "3 dots" in the upper right corner -> "Battery optimization" -> select "All apps" from the dropdown menu  and disable battery optimization for every bluetooth service app, as
- Bluetooth MIDI service
- BT Tool
- Bluetooth sharing

and for every app needing to use bluetooth to transmit data, as
- Phone
- Phone services
- Call management
- Phone/Messaging storage
- your 3rd party music player
- other telephone dialer apps
- fitness band apps and so on

3) Only if the previous steps doesn't solve your issue, also
- Go to "Settings" -> "Battery" and disable "Standby intelligent power saving"
- Go to "Settings" -> "Duraspeed" and and disable it.

4) Only if, again, the previous steps still don't solve your issue, also go to "Settings" -> "Battery" and set your device into "High performance mode"

Please follow these steps carefully

Hello.
I followed all the steps but it does not work ...

I will wait for an update of the phone

Neville wrote:

nonobike wrote:

Hello. 
I want to connect my Garmin Fenix 5 to the BV8000 pro in bluetooth. 
the syncronization worked once ... now it is connected in bluetooth but impossible to syncronized the application. 
Have you ever had trouble with blue equipment? 

Thank you for your help

Fenix 5 is older tech and may have compatibility issues with Android 7 and 8 onwards (Google introduced new security protocols in 7x after discovering older connections could be used to hack into phones…)
 
https://www.google.com/search?q=garmin+fenix+5+nougat&ie=utf-8&oe=utf-8&client=firefox-b

Hello. 
I'm really not an isolated case ...
 I'll wait for an updated blackview! a lot of DIY solution we found but nothing reliable ....