I'm experiencing something similar (I guess) with my BV6000 bought 5 months ago. It's ONLY during on-going calls on handsfree mode, using speaker (via phone or whatsapp) that the other one can not listen to me. I can easily record voice or create videos, so, I understand this is not a physical problem. I already increased the UL gain to 240 and similar results. I've been writing to Blackview support in Spain and after two attempts, they're not responding to me. Also I tried with Blackview support in HongKong and they only answered to me with the standard solutions (factory reset,execute hardware tests...) and now they've stopped responding to me.
On my BV6000 I do not find the option mentioned on this server about disabling noise reduction in "Telephone App --> Settings --> Accesibility". There I only have "TTY mode" options. Any solution for this? As you can imagine, it's quite annoying that even the official support from Blackview in two countries are not providing solutions for my problem.
Hello, sorry to reply to you. You can contact our professional after-sale department: firstname.lastname@example.org