issue with alerts

 

Hello mql5, I have a problem with MT4 and also MT5 Android version If I have unlocked my phone, I receive push notifications (alerts from MT4 Windows), but if it is locked for more than 5-10 minutes, I did not receive it only when I unlock my phone. I have a Huawei P20, I tried with another P20 and one Samsung, but the same problem on all devices...

Any advices? (I'm sure, my mobile is not on battery optimization and MT4 is running in the background).

Thank you.