Unfocused2257 As @Galt007 said, you need to ensure you've got direct line of sight to the sky (preferably outdoors) and to use https://play.google.com/store/apps/details?id=com.android.gpstest&hl=en&gl=US (via Aurora if on a non GPS profile or Play if GPS installed).
The first lock can take between 2-5 minutes while extra data is downloaded:
HTTPS connections are made to fetch PSDS information to assist with satellite based location. These are static files and are downloaded automatically to improve location resolution speed and accuracy. No query or data is sent to these servers. These contain orbits and statuses of satellites, Earth environmental data and time adjustment information.
On prior generation Pixels with a Qualcomm baseband (which provides GNSS), almanacs are downloaded from https://path1.xtracloud.net/xtra3grcej.bin https://path2.xtracloud.net/xtra3grcej.bin, https://path3.xtracloud.net/xtra3grcej.bin, https://path1.xtracloud.net/xtra3Mgrbeji.bin, https://path2.xtracloud.net/xtra3Mgrbeji.bin and https://path3.xtracloud.net/xtra3Mgrbeji.bin which currently (as of May 2022) are hosted via Amazon Web Services. We plan to offer the option to download these files from the GrapheneOS servers, but we'll retain the option to use the standard servers to blend in with other devices.
On 6th generation Pixels with a Broadcom GNSS chip, by default almanacs are downloaded from https://google.psds.grapheneos.org/lto2.dat, https://google.psds.grapheneos.org/rto.dat and https://google.psds.grapheneos.org/rtistatus.dat which are the GrapheneOS proxy servers for the standard servers. Alternatively, the standard servers can be used which are https://agnss.goog/lto2.dat, https://agnss.goog/rto.dat and https://agnss.goog/rtistatus.dat which currently (as of May 2022) are hosted via Google Cloud Platform.
Let us know if any of this helps and we can move forward troubleshooting.