Help Bluetooth Controller lag

[MyLegGuy]

So, I'm using a wireless controller with Bluetooth to play a game and I get some controller lag. However, for the first 10 seconds or so there is no lag. Then the lag kicks in. If I go to the android home screen thing then back into the app then the lag is gone for another 10 seconds or so. It's really big lag. If it matters, I'm using a ps4 controller. I connected it using a method on a Youtube video:

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I'm on a Nexus 7, Android version 5.0.2 I think.

So, anything I can do?