iPhone X Freezing

Hello Apple community,

I have quite a strange issues with my X. So I got my phone 7 months ago and back than on iOS 11.2.1 was laggy, freezing, the vibrator motor was acting weird and etc and etc. Trough time some of the bugs appeared from time to time, but the most common thing was the freezing part where I had to restard my phone. It was strange! Even through summer it happen me quite often. On iOS 11.4 things were good, just sometimes, but now with iOS 12 all my issues were gone, including the vibrator acting weird. Like making crackling sounds like it is going to brake any moment. But in the last two weeks since iOS 12, my phone froze up again, twice. Yes, other issues are gone, but this still goes on sometimes. Works awesome, but what could the issues be? Thank you in advance!