May you have the same issue: my new BV 9800 pro doesn't recognize other bluetooth devices like headphones.
I had BV 8500 pro before and bluetooth was always problem there - initially turning on bluetooth always re-booted device, after few months and multiple firmware updates issued by Blackview it started work but still re-boots from time to time. It is dissapointing that bluetooth is also a pain in new BV 9800 pro... Do you have the same? Could anybody from BV confirm when can we expect firmware update for that problem?