This changes how a number is computed. Your charts can move without your data moving. Each change is named below with the reason for it.
Which number changed
Time Tracking → Workflow Bottleneck Detector → Impacted tasks: the time shown for each task, its "% of status" and its "% of avg".
Direction
Up for tasks with more than one assignee. A task with two assignees that waited 10 days in Review used to show 5 days; it now shows 10. Tasks with one assignee keep the same time, but their "% of status" and "% of avg" can move slightly, because the status total they are compared with now includes everyone's full time.
The status totals and averages at the top of the detector do not change. They already counted each task's full time.
Why
Time in a status is waiting time on the calendar. A task that sat in Review for 10 days waited 10 days, however many people were assigned to it. Splitting it between assignees made the task list disagree with the status total: you could add up every task under a status and not reach the number shown for that status.
The list now adds up to the status total. When a status has more than 100 tasks, the list shows the 100 longest and says so, for example "Top 100 of 219 tasks, 3y 6mo in total", so a shorter sum is never a surprise.
What to do
Nothing. If you exported or noted per-task figures from this list before, expect multi-assignee tasks to be higher now.
Very large totals usually come from a few tasks that sat in one status for months or years before being closed. They are real time in the tracker, not an error in the calculation.