I have re-watched the Buffy Series and the Angel spin off afterwards. The last 4 seasons of Buffy and the first 4 seasons of Angel were happening concurrently. There were also a few intersections between series storyline in this time:
Like Buffy sending the gem of Amara to Angel, Angel going to Sunnydale to save Buffy, Angel finding out about Buffys death, Faith going to LA after the body swap with Buffy...
In Season 4 of Angel, Jasmine brings world peace temporarily
before Angel kills her.
In the last Episode of Season 4, Angel gets some intel about the events happening in Sunnydale (during the last season of Buffy). So clearly the "world peace time span" occurs before the finale of Buffy, yet there was no peace in Sunnydale.
So my question is why were Sunnydale and the Scoobies & Slayers not affected by the world peace?