Mr Steel Hi, I am also experiencing the same issue. I have repeatedly reformatted my phone, but the issue of growing system files persists. I also notice that when I am connected to the internet, the size continues to grow, and the phone overheats.
In search of a solution, I arrived at this thread and followed your advice. There are no logs listed, and the app info for the log tool does not show any relatively large amounts of data (KB size).