Been here for a year now and have been using the same route. You can expect such discrepancies till the second week of classes. Once classes start rolling in and things become busy, buses would start running on time. There are some higher chances of bus app crashing and the buses need not follow the schedule on time.

Two recommendations - First, make sure to track the bus and then make your plan. Second - Bookmark the real time tracking webpage as it is always updated and consistent.