With default settings iNav will configure the GPS automatically, there is no need for configuring it manually using software like u-center. With default iNav settings iNav will configure ublox GPS for you, no need to use software like u-center. Also be aware that some of our flight. This wiki topic describes the software currently available and some of the RTH and you don't have a good accuracy GPS fix; You try to arm into RTH/PH/WP.
INAV: Navigation-enabled flight control software. INAV is a fork of cleanflight with a heavy focus upon GPS features for both airplanes & multirotor models. iNavflight is a fork of Cleanflight which is designed to make the best of GPS and navigation capabilities. Cleanflight and Betaflight don't have the best GPS. iNAV Philippine Corporation - the solution provider for Philippine GPS Navigation System.