I have bought Nokia 7 plus 2 weeks ago and here's the problems I've found
1- (System UI is not responding). It happens with strange lag that my phone is not responding to any action I take for about a min. This problem appeared after Android pie.😠
2- Bluetooth is not working at all. This problem appeared after Android pie.
3- I think there is wrong with new battery efficient feature in Android pie. As my battery keeps draining fast. And of course this problem appeared after Android pie.🤔
4- The lack of in-built AppLock. This is so serious problem as it feels unsafe.😷