Thanks for your reply!
I tried all your suggestion (1 – 7), but the LG G4 still cannot get paired.
Actually, the meter working fine on my Samsung S4, so the meter itself should not have any problem.
And the LG G4 also working fine with my Bluetooth headphone, so I think the LG G4 Bluetooth should work.
I gave u more detail info.:
Mooshimeter App Version 1.0.17(444)
Mooshimeter V.1 Build:1445847981
Model number LG-H818N
Android Version 6.0
Build number MRA58K
Software Version V20e-HKD-XX