I tested a 23byte data transition in iPhone 5s with Softdevice 3.1.0, sdk12.2 . it is ok. I know that iphone 5s is ble 4.0.
So I thought it would be possible on Android(Galaxy tab s, samsung, ble 4.0).
in nRf connect tool, I sent 23 bytes, but only 20 bytes.
Can not send more than 20 bytes at a time in Android platform BLE 4.0?