I found Vuforia's performance decrease on low spec Android devices.
After few moments with 60 fps app starts to freezing, profilling in Unity shows that "unaccounted time between: InputProcess and InputProcess"
grow over time from 0 to 98% of CPU usage. It can be reproduced even with Vuforia's examples.
On Unity 5.5 with Vuforia 6.2.10 everything is OK, fps are stable.
- Asus Zenphone 2 Laser ZE500KL.
- Unity 2017.3, Unity 2018.2, Unity 2018.3
- Vuforia 7.2, Vuforia 7.5.26
I can provide adb logs or some profiler datas if needed.