ProximitySensor | Proximity Sensor Android

There is an app that uses play games service, but by some reason it stops working. it looks some times i can login successfully but usually - no. if i checked API traffic there is about 10% got response code = 200, and others - 404.

methods that get 404:

• games.applications.played
• games.events.record

when i tried to check error in log i see:

I'm trying to use the ProximitySensor in QML. I didn't find examples of how to use it. I'm using QtSensors 5.0. I tried get if something is near by calling the reading property, but this property only have this properties: deleteLater, objectName and timestamp. I tried this ProximityReading.near, but it returns undefined. I also tried this proximitySensor.close(), but it returns that proximitySensor was not defined. The proximity sensor is working fine, because I tested in my smartphone the property reading.timestamp and the values was updated properly.

My code is something like this:

I am trying to resolve this annoying bug and I have tried every possible option. I went through the previous SO answers and tried invalidating caches and restart. I also made sure that my support dependency in gradle are correct but for some reason my app crashes when I run it on my phone with the following errors.

I would like to use the Bluetooth Low Energy (BLE) technology to make connection between two supported phones (currently I would like to use it with only Android phones, iOS support is possible in the future). The client which starts the connection should be an Android device with API level 19 (KitKat) or above.

I've read several tutorials and tried several examples about how to achieve a working Bluetooth LE scanning on Android (including Google's own sample project called BluetoothLeGatt). The following things are already done in my test project, based on Android documentations and many SO questions and answers:

• Minimum SDK version is set on API level 18 (that's where Android started to support Bluetooth LE)
• The mandatory Bluetooth permissions (BLUETOOTH and BLUETOOTH_ADMIN) granted in AndroidManifest.xml, plus the android.hardware.bluetooth_le feature is set with true value
• The ACCESS_FINE_LOCATION and ACCESS_COARSE_LOCATION permissions are also needed on API level 23 and above - so they are in the manifest file too (with uses-permission AND uses-permission-sdk-23 tags), plus the android.hardware.location.gps feature is set
• The user also is asked to grant the permissions mentioned above at app's first start
• Bluetooth and Location (GPS) are turned on
• Scanning for devices starts after permissions are granted (managed with clicking a button)
• On API level 21 and above the newer API methods are used instead of the ones deprecated since the same API level

Despite all the things listed above, NO DEVICES FOUND AFTER STARTING THE SCAN. Currently I'm using a 6.0 (Marshmallow, API 23) device and everything seems fine - except finding the devices around me with Bluetooth turned on and set to always visible. But of course, from the device settings I can find all of them, so I don't understand what could be the missing / wrong thing (by the way, it's the first time I'm dealing with something related to Bluetooth... :) ). It looks like the scanning process starts seamlessly, but none of the callback methods are responding any single message or variable.

And YES, I KNOW: there are a lot of questions on SO about this with people saying "everything works after making the changes above"... and unfortunately it does not work for me, so I'm a bit frustrated about this problem. If anyone reading this topic faced before with anything similar to this, and writes a comment or answer down there, I will really appreciate it! :)

TO MAKE THE QUESTION SECTION EVEN LONGER:

My activity: