Intervals of spikes of Graphics.PresentAndSync show up in profiler

Hi everyone,

after playing a simple build on Android phone (LG G3) I have noticed that after approximately half a minute of smooth gameplay, game starts to slow down. I opened the profiler and saw that spikes of Grap$$anonymous$$cs.PresentAndSync shows up out of nowhere and keeps showing up in certain intervals. It slows down gameplay drastically. I tried with simple scenes and even empty scenes without any object and without any elements on camera being turned on. I tried with all these t$$anonymous$$ngs along an empty scene and without any luck:

-vsync off
-quality settings on fastest
-power saving mode turned off on phone
-setting targetFrameRate to 45 (just lowers down height of spikes a little bit, but with no luck - second screenshot)

And also problem is showing up when it is not development build and not connected to Profiler.

Does anyone knows what turns on Grap$$anonymous$$cs.PresentAndSync and how to deal with it, so gameplay could run smooth as it is at start?