Pixel 8 'OEM unlock' greyed out

The phone is a brand new phone that was provided by my carrier in Canada (Telus). The phone is carrier unlocked. I verified this by putting a non Telus sim into it and making a call. Once the "Developer Options" menu is enabled, the "OEM unlock" is greyed out, I tried the following in all kinds of order: - factory reset... many times - all software updates - connection to the internet (via wifi) - Using android recovery I performed a factory data reset in the erase Wipe data/factory reset option - enabled "USB debugging" in developer options - I asked chat GPT and tried all the options that were technically possible. When I look on the "Fastboot Mode" screen, the device state is locked. I called my phone provider, and the technical support is trying to help, but I don't see that working out. Does anyone know of a secret menu that allows the enabling of this setting? What can I do?