Framerate drop due to increasing VSync times

Hi,

We have a simple android game which suddenly slows down a lot, to under a frame a second. It happens at random, sometimes five minutes after the game has been launched, sometimes it hasn't happen after 20 hours. The game is under the specs of the used device and the log files do not show any exception/errors.
I finally got a few frames of profile data for it. It can be reached here:
https://trackman-my.sharepoint.com/:u:/p/ppe/EZF_kOlUOWlOpzX8aKW4Ee8BnRcgY9DULEvHGPR5K70ybA?e=QXy016

Two data points, first frame VSync = 7850 ms and last frame(17) VSync = 443472 ms.




We do use Application.targetFrameRate = 30, We set it on an gameObject in the first loaded scene, in the start.

Do anyone have any idea of how to approach this bug a little further?

Any help is appreciated.

Best regards Povl

 

So update. Got a tip about some deep profiling and turning of VSync for android.
It turns out it is related to Semaphore.waitForSignal:

All other threads seems to idle as well, when looking at the timeline view:


Any ideas would be much appreciated.