Ty for these messages. I am having a similar issue on a new Pixel 9a I'm setting up with GOS for a family member.
Toggled on eSIM support, tried both manually entering eSIM code and taking picture of QR code for eSIM from my carrier, and both received the message "SIM not activated - Something went wrong while trying to activate your SIM".
I got multiple QR codes from my carrier and different networks, none work. Did a factory reset, same thing. I've now ordered a physical SIM card and will try with that once it arrives.
I currently have GOS on my own Pixel 9a with eSIMs through the same carrier, which I activated several months ago, and no problems there. Also no problem with another family member's Pixel 6a running GOS which was activated several months ago as well.