Google has limited API for call recording to system apps in Android 4.4. But some developers have found workarounds to these limits and these workarounds worked till Android 8.1. But these workarounds will no longer work on Android 9 Pie, unless you have a rooted device.

Who affected?
This change will affect all third-party call recording apps on Android.

Will it be fixed in the future?
It depends on operation system developers and device manufacturers.

Current workarounds for non-rooted devices

• Use System Recorder method, if your device has built-in call recording
• Turning load speaker while in call
• Setting recording mode to Stereo and try to find the best suitable volume control values for your device (E.g. Left: 50%, Right: 800% for Pixel 2)
• Repeat important information during a call

Questions?
Contact me at m@skvalex.org