Hi. My Nokia 7 worked OK with Oreo 8.0. Official 8.1 was updated 12.5, there was some download error at first but later download and installation went smoothly. After update phone does not connect 4g network and mobile data is not working with 2/3g so phone is pretty useless when out of WiFi. Checked APKs as well 4g recommended connection is choose. Resented also connection setting, no help. Any advices please?