Sorry, I don't understand what the problem is here.
Describe what you are seeing in your bug report.
Paste in the text of the error message that appears in the console.
Indicate the steps that lead to the error.
If it doesn't happen all the time, mention that in the bug report.
If at all possible try to find a way that the problem can be reporoduced on demand.
Don't feel as though you are confined to the bounds of the use cases. I'm not saying go ahead and do some full-blown exploratory testing, but if you find a bug that is not within the linear path of the use cases, it's still a bug. The customer will still find it.
If you can reproduce the issue on demand, then you need to report it and someone needs to resolve the issue. Otheriwse, if it is an issue with your environment, then you need to be set up with a proper testing environment. Either way, this is still a bug.
9 out of 10 people I prove wrong agree that I'm right. The other person is my wife.