In the Budget account page the summary page of category groups does not indicate a category which has exceeded the budget amount. When one drills down into a group category an "overdrawn" category is in red and easily discernable. Not so in the summary page.........so unless one is constantly drilling down an overdrawn category can be easily overlooked.
In the old version of YNAB it was very easy to expand the budget to show all categories, not so in this web version. perhaps you could Meacham to sort out this oversight.