I have written many problems before, but this is the first time I have encountered this issue
While working on some problems recently, I encountered issues like this more than three times across different problems. All the tests are fine, but messages like these still appear:
This is the validator
These are some test cases of the problem
Probably the statement or the legend is messing up the machine learning system that deduces the limits. There are some blogs on codeforces (i can't reach them now) describing the same thing. I even faced the same issue a while back. The common thing is that there were a complex equation in the legend that includes the same variable name in the input section (usually n).
I think that can be because in statement you put lower_bound for n 2, but in validator 1.