Recent Huawei phones have a feature named "Protected Apps", you can control an app to allow / disallow it receive notifications when the screen is off.
You should set Boldbeast Recorder as a Protected App, otherwise sometimes when a call comes the ROM doesn't notify the recorder, therefore some calls may not be recorded. By setting Boldbeast Recorder as a Protected App it works perfectly.
Please in the built-in "Settings > Power saving > Protected apps" screen to change it.
Some phones may be in "Settings > Phone Manager > Protected apps".
Some phones may be in "Settings > apps > advanced > Ignore Optimizations".