I was having this problem and found a fix simply by editing the file gps.conf located in /vendor/etc (root needed) changing the ntp server to my country which in this case is Brazil.
How it was:
#NTP server
NTP_SERVER=time.izatcloud.net
NTP_SERVER_2=asia.pool.ntp.org
NTP_SERVER_3=0.cn.pool.ntp.org
And now is:
#NTP server
NTP_SERVER=time.izatcloud.net
NTP_SERVER_2=south-america.pool.ntp.org
NTP_SERVER_3=0.br.pool.ntp.org
After this my gps accuracy improved a lot locking position even when I'm inside the house