Samsung usually enables or disables the call recording feature by market areas.
Please see  on this page http://www.boldbeast.com/android/call_r … oting.html to use suggested settings to record calls. If recordings are good, that's great. If your voice is good but the voice of your friend is weak or silent in recordings, you should:
- Switch on the loudspeaker during a call, so Boldbeast can record the call on both sides normally. Or
- Root the phone, so Boldbeast can fix it completely to record calls on both sides perfectly without switching on the loudspeaker.
Samsung Z Flip has the Qualcomm SM8150 Snapdragon 855 chipset inside. Most phones on the market that use a Qualcomm chipset has bluetooth recording problems. This is because the audio driver provided by Qualcomm has bugs inside. Only a few manufacturers fixed the bugs in their phones. Most manufacturers didn't fix them, as a result you can only record your own voice or can only record the caller's voice via bluetooth.
Boldbeast Recorder can fix the bluetooth problems if you root the phone. After root the phone please:
- In Boldbeast Recorder tap "Call Settings - Manually Record Calls - Hotkey" to open the Accessibility settings screen, enable Boldbeast Call Recorder accessibility service on the screen.
- Use these settings to record calls:
Record Mode: 12
Fix Recording Issues - Tune Audio Route: Group1
Fix Recording Issues - Change Audio Controls: Yes
Now you should get crystal clear call recordings via bluetooth.