I've try this method to get my oreo update
go to setting>apps>menu(3dot)>show system>choose Google service framework>dear data & force close.. after that try update your phone.. no issue for me at all with the oreo update.. battery consumption seems better.. and the charging time is slightly faster than before.. this morning I've tried using Waze to work while using umobile.. seems the problem gps lost signal is solved with this oreo update.. that's is a good news for me.. 😁 😁 😁

yup I faced this bug too..