I was tired of waiting any ota,yesterday i bought easy firmware silver package and downloaded service firmware 9.1.0.370 EML-L29C432E10R7P12,i made the dload method with usb stick on my P20 EML-L29C432E7R1P11 who was on 9.1.0.328 long time,theorced update with stick was 100% secure and it booted in time,without mistakes,now i am on version 9.1.0.370 with device certified,if anyone wants that firmware i can upload for you