Just to give some 3rd party perspective, I am on Cox and there is something similar with diagnostic menu of the DPC3010. From what I understand, the firmware is set up in such a way that it can either give total access or very limited access. Since they don't want user to be able to control things like channel ID and possible break their connection (and cost them a truck roll) they go limited, which has the side effect of hiding the logs.
Just for kicks, give this a try. After a normal boot, when you can't see anything, try going Alt+V > Style > No Style. See anything different? DPC3010 its locked at firmware, yours seems more locked by config file.
I actually changed the upstream channel to 3(A channel I don't have) and it actually went through but once it fully reconnected it went back to default I assume lol. I tried what you said and didn't see anything different .