I don't know if this is related (or another bug): I can reproduce 100% on OTA-10 with the app SensorStatus, that the app opens successful the GPS service, issues some ioctls and without getting or waiting for a first fix, it just closes again the GPS, all this within 2 secs:

$ tail -f /var/log/syslog | fgrep GPS

Apr  8 08:48:48 ubuntu-phablet kernel: [  668.400623] (2)[1213:mtk_wmtd][WMT-CTRL][I]wmt_ctrl_gps_sync_set:ctrl GPS_SYNC(4)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.400669] (2)[1213:mtk_wmtd][WMT-FUNC][I]wmt_func_gps_pre_ctrl:ctrl GPS_SYNC_SET(0) ok
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.401061] (1)[1213:mtk_wmtd][WMT-FUNC][I]wmt_func_gps_pre_ctrl:set reg for GPS_SYNC function okay by chip ic_pin_ctrl
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.401191] (1)[1213:mtk_wmtd][WMT-CTRL][I]wmt_ctrl_gps_lna_set:ctrl GPS_LNA(2)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.403702] (3)[1074:mnld][GPS] [I]GPS_open: WMT turn on GPS OK!
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.403753] (3)[1074:mnld][GPS] [I]GPS_compat_ioctl: (8)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.403769] (3)[1074:mnld][GPS] [I]GPS_unlocked_ioctl: GPS co_clock_flag (0)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.404403] (3)[1074:mnld][GPS] [I]GPS_compat_ioctl: (7)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.404419] (3)[1074:mnld][GPS] [I]GPS_unlocked_ioctl: low power flag (0)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.406411] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21505)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.406429] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21505)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.406445] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21506)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.406459] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21506)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.406474] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21515)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.406487] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21515)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.407859] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21505)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.407880] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21505)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.407896] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21506)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.407910] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21506)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.407925] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21515)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.407938] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21515)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.418189] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21505)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.418211] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21505)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.418228] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21506)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.418264] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21506)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.418281] (1)[8506:mnld][GPS] [I]GPS_compat_ioctl: (21515)
Apr  8 08:48:48 ubuntu-phablet kernel: [  668.418294] (1)[8506:mnld][GPS] [I]GPS_unlocked_ioctl: unknown cmd (21515)
Apr  8 08:48:50 ubuntu-phablet kernel: [  669.680710] (1)[1213:mtk_wmtd][WMT-CTRL][I]wmt_ctrl_gps_sync_set:ctrl GPS_SYNC(7)
Apr  8 08:48:50 ubuntu-phablet kernel: [  669.680741] (1)[1213:mtk_wmtd][WMT-FUNC][I]wmt_func_gps_pre_ctrl:ctrl GPS_SYNC_SET(1) ok
Apr  8 08:48:50 ubuntu-phablet kernel: [  669.681611] (1)[1213:mtk_wmtd][WMT-FUNC][I]wmt_func_gps_pre_ctrl:set reg for GPS_SYNC function okay by chip ic_pin_ctrl
Apr  8 08:48:50 ubuntu-phablet kernel: [  669.681671] (1)[1213:mtk_wmtd][WMT-CTRL][I]wmt_ctrl_gps_lna_set:ctrl GPS_LNA(7)
Apr  8 08:48:50 ubuntu-phablet kernel: [  669.683691] (1)[1074:mnld][GPS] [I]GPS_close: WMT turn off GPS OK!
Apr  8 08:48:50 ubuntu-phablet kernel: [  669.654292] (1)[1964:tx_thread][GPS] [I]GPS_read: signaled by -ERESTARTSYS(-512)