Hello all,
I have bought brand new PIxel 9 some time ago. After installing GrapheneOS, I noticed that the phone keeps losing connection to the carrier (mobile data does not work too). The phone always connects, but after a while the connection is lost (The signal strength indicator shows "No service" or **"No SIM, No service"*).
Thinking it is hardware problem I have sent it for repair. The phone was returned with "software issue" explanation (fix: software re-image) and with the stock Pixel OS installed. It worked correctly. Funny part about this is that I installed the stock Pixel OS myself before sending it for the repair and it did not work. Based on this I think it needs some software tweak/config/driver or whatever (I do not understand much about Android or carrier networks).
I tried it with two physical SIMs (each from different carrier) and an eSIM, but the problem persists. Today, I also noticed that every time the connection is lost, the SIM/eSIM used is listed as "Unknown" in the settings app (even though it is in the phone). It seems to me that sometimes the phone is unable to detect/read the SIM/eSIM.
The loss of connection seems to be random, movement does not seem to affect it. Sometimes the phone keeps the connection for several minutes, sometimes the connection is lost after only few seconds. Or it does barerly connect; I was desprately trying to send an SMS for about 30 minutes this morning...
I did try, but I did not find any issue that exactly resembles my problem. The closest one should be this one (but the problem is happening since installation and persists on the stock Pixel OS when not installed by repair shop)
Information:
Model: Pixel 9 (256GB)
Carrier: T-Mobile (europe)
OS: Latest stable (should be 16(BP4A.260105.004.E1)