Try the workaround posted in this thread (
viewtopic.php?f=191&t=333190&start=70 ) and report back if it solves your issue:
0)
Update you device to the latest firmware and perform a factory reset after that1) Disable battery optimization for every bluetooth service as
-
Bluetooth MIDI service-
BT Tool-
Bluetooth sharingand for every app that will need to use bluetooth to transmit data as
-
Phone-
Phone services-
Call management-
Phone/Messaging storage- your music player
- other telephone dialer apps and so on.
-
EXPECIALLY THE APP THAT YOU ARE USING FOR YOUR FIT BAND2) If the previous step doesn't solve your issue,
ALSO disable the "Standby intelligent power saving" setting and
disable Duraspeed.3) If the previous step doesn't solve your issue,
ALSO set your device into "High performance mode"