- Insert China Telecom(CHN-CT) sim card, edit APN settings as the same as Android system.
- check the list of ISP, only List CHN-CT.
- Celluar Searching for 3～5 minutes, show me Denied.
because Pixel 2 XL not fully supported China Telecom, in Android system I can modify Vendor partiton(copy .mbn files from other phone, edit oem_sw.txt).
so I just boot TWRP. the I can mount Vendor partiton and modify it. after this i do a factory reset in ubuntu touch os.
then do a new testing, but no miracle. phone app says "no service" and Celluar Denied.