Just to let everyone know that in my case it was indeed a hardware issue. The official service center replaced the mainboard under warranty, and I have not experienced any camera issues since.
I'm sorry to disappoint those who have issues with the front and main cameras not working. The Android 14 update (34.0210.0210.241) did not fix the issue for me. I just sent my ROG Phone 6 to the repair center today.In my case, it seems to be a hardw...