BLE startNotification Problem

Hello guys, how are you doing?
Well I have a problem using BLE on android 7.
I´ve tested my app on many versions like androind 6.0 and android 8, it seem to work fine on those ones,
but on android 7 it doesn´t work good.

I´m connecting to a BLE pheripheral then receiving data from it. But when I try to receive data
(with ble.startNotification() function) it doesn´t work on Android 7, but works on lower and higher versions.

Please if anyone can help me, I apreciate a lot.
Thank you