I ran GrapheneOS for a couple days to try it out, but decided to move back to the stock Pixel OS. Upon returning, my eSIM would not turn on anymore. I tried removing it, and kept getting errors. I can't even reset mobile network settings without getting an error. Trying to add a new SIM results in "SIM not activated" no matter if I'm on Graphene or Pixel. Trying to reset mobile network settings leads to "Can't erase eSIMs. Something went wrong and your eSIMs weren't erased. Restart your device and try again." Unsurprisingly, restarting does nothing.
I even tried reinstalling GrapheneOS and typing in a Duress PIN to reset everything on the phone, and still cannot add an eSIM.