I too am starting to have this issue . A reboot does fix the problem but that isn't really a fix ,now is it? I have already missed a few calls because of this problem.
Did the full reset help anybody?
The more I use blackview products , the more I am starting to dislike them...

Hello,

Where can I download the latest firmware/ROM for my BV9500 (not plus)? My phone currently has build number: BV_BV9500_V1.0_20180814 . All the mega links ( as some other users have already stated) are dead.

Thank you