Phone sometimes frizzes and works nothing like a phone with snapdragon 630 inside.
I did factory reset and the problem still persists.
And I probably found the reason it happening. The problem may be in poor memory allocatin and reclaiming handling (software or hardware)
You can download an application that fills phone RAM (like MemoryPump from google play). I have tested it on my Pixel 2 (android 8.1) and on Samsung Galaxy s4 mini (android 4.4). Both behave as expected: when device gets low on memory, system kills application that causing a problem. Full memory allocation until application gets killed doesn't hang ui and happening in 10-20 seconds.
On the other hand when I trying to do the same with Nokia 6.1: memory allocated much slower. UI is unresponsive. In a minute screen turnes off (no ANR for some reason), Power button also doesn't respond for another minute. Then phone turnes on again (like after reboot or something)
Any way there are definitely issues with camera and ui sometimes.
Should I contact service center in Russia, or this behavior considered as normal?