Bluetooth problems after Android L update topic

I wrote an Android application that control an RC car. The phone and the car communicates by bluetooth. I have tested the application with several Android based phones. The Os version was 5.0 and lower. I had problem with only one phone. That was a Nexus 5 with the newer version of Android. After the new update arrived to my phone, i just updated my phone. I changed 4.4.2 to 5.0, I have an LG G3. Unfortunatly after the update the problem occured on my phone too. The problem is that after the phone connected to the car the data send is getting laggy and slowing down and the car cannot be controlled, sometimes it work fine for few seconds. On every other phone I have tested the application it worked fine.

Anybody knows anything about that problem?

Thank