The issue has been fixed by just walking outside and letting the map load. For some reason it did not happen while I was inside a building.
Yes with the default redirect to the OS Location API you need direct line of sight to the sky and a couple of extra minutes on first lock to download the almanacs.
All covered here:
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.
By default, apps using Google Play geolocation are redirected to our own implementation on top of the standard OS geolocation service.
Re-routing location to the OS geolocation service will use more power than using the Google Play geolocation service since we do not provide a network-based location service and implement it via GNSS / A-GPS only.