When im speaking to someone they can hear themselves echo bad rather badly, I cannot hear this from the headset.
Is there a easy fix as in software ? or is this more likely to be a hardware issue. 
Ive only had the phone for a week. 

no this does not happen during hands free.

only during normal calls, if I turn the call volume to 0 only then does the issue go away for the other person. Im wondering why I can still hear them if its set to 0, is this a faulty speaker?
I have tested this by calling 2 other phones they are on different carriers, when making adjustments on the 9900pro from hands free to normal and back again when calling these other phones then problems happens exactly the same

No echo when on hands free, and once the in call volume is turned to 0 then the other person cant hear the echo

Build number:

BV9900Pro_EEA_S900AA_V1.0_20200601V09

To me it's sounds like the microphone on your phone is picking up what the person at the other end is saying and is feeding it back to them, is it any better if you hold the phone slightly differently or have a lower volume on the speaker.

Did you upgrade to Android 10 . Is the Call Echo still there on Android 10 ?

phonebs wrote:

Did you upgrade to Android 10 . Is the Call Echo still there on Android 10 ?

Hello, we will announce the notify if it can be upgrade.

phonebs wrote:

Did you upgrade to Android 10 . Is the Call Echo still there on Android 10 ?

Hello, we will announce the notify if it can be upgrade.

On the official website  https://store.blackview.hk/en/buy/bv9900pro say: Newly Updated: BV9900 Pro is Android 10.0 Now!
It shows that new phones are sold with Android 10. Why do you state to Not upgrade to Android 10 because it is not stable?

The issue I was having wasn't resolved after a tech person looked at the phone, so I have since sent it back to where it was purchased from and got a replacement, the new unit doesn't have the issue and all functions as normal, so was a faulty unit not a setting.