SSBLV2 only show 3 weeks after cancelled event

The event I was training for was cancelled and now my plan, having just completed SSBLV1 (plan builder) is showing 3 weeks of SSBLV2 then 2 weeks of specialty and then after that nothing, even though I have moved the event to 20th sept on the calendar. How can i change my plan to continue with SSBLV2 so it’s 6 weeks as it should be and then plan builder does the rest after that with build/specialty etc.
Thanks, loving TR, the podcast and the forum.