I just purchased Nokia 7 +. Android 8.1.0, security patch 1. April 2018, software version 00WW_2_22A. It hang up continually seemingly without any specific reason. Phone can be started up again with pressing long time power + volume buttons together. What is wrong?
Try to update the phone up to August patches, that build should solve most issues.
I did the same but barely used the phone before, so my experience is excellent from the start.
Basically , you should get them consecutively . If not appearing on themselves, try manually in system/system update submenu.