I'm having a strange issue with Google Fi on GOS. Last night, Google Fi suddenly notified me that it was not fully activated. I have a physical SIM, so I thought that might be the issue and removed it to try and reactivate with eSIM. However, after removing it, it still is displayed in the SIMs setting menu, even after reboot. If I try to activate with that SIM enabled, Google Fi gives me a "Your sim card cannot be read" error even though it's fully removed. If I disable it, I'm able to start the eSIM provisioning process through the Fi app, however it hangs on "Just a moment" forever (or at least more than an hour, I gave up around that time). For a moment last night, I was able to get service back, but I didn't actually do anything (in fact, I was searching to see if any retailers had Google Fi sim cards at the time when I noticed I had service again). After awhile though, I lost service once again.

I looked at a bunch of different threads here and haven't been able to resolve this issue. Some of the things I've tried:

Granting all permissions to Google Play Services and Google Fi
Inserting my physical SIM, disabling eSIM, and rebooting.
Removing my physical SIM, enabling eSIM, and rebooting. This results in a "ghost" SIM that doesn't seem to actually work, and I must disable this SIM to have the eSIM provisioning process actually start through the Google Fi app. However, the provisioning process never finishes, and hangs on "Just a moment".
Checking if DSDS is enabled in the phone information menu. It was already enabled, and disabling and re-enabling it did not fix the issue, even after reboot.
Reinstalling the Google Fi app, and retrying all combinations of physical SIM and eSIM.
Enabling unrestricted data usage for the Google Fi app

The only thing I've seen that I haven't tried is enabling "Privileged eSIM management" which I cannot find under Settings -> Network & Internet.