Just checked the firmware version, and I strongly suspect we are very outdated.
AT+QGPS? +QGPS: 1 OK ATI Quectel EC25 Revision: EC25AFAR05A04M4G OK AT+CVERSION VERSION: EC25AFAR05A04M4G Aug 18 2017 17:10:17 Authors: QCT OK
2017 seems pretty old.
Please send me by e-mail both the latest stable and compatible firmware image, as well as the detailed procedure on how to update on Linux.