It sounds like the same thing that happens on the Samsung A50 with updated Android 10 When using the phone as a speakerphone the display goes blank. You can bring the screen back to life by clicking the power button or pressing the home button area. I have not been able to find a setting to change that behavior.
flash your android 10 software. which is recommended process to update any big os ...simply mobile data or wifi se download karne se aisa hi problem ate hain jo actual procedure hi nehi hain big software update ka
