New Girl and Brooklyn 99 created a shared universe with their crossover episodes, but one New Girl cameo causes a big plot hole for that universe. New Girl and Brooklyn 99 had two crossover episodes, one for each show, which saw the New Girl cast travel to the east Coast for Schmidt’s (Max Greenfield) high school reunion. Both shows were airing on Fox at the time, and the crossover episodes aired consecutively to create one continuous storyline. The crossover was most likely intended to boost numbers for both shows, but the two shows share a lot of the same actors which caused some plot holes.
https://screenrant.com/brooklyn-99-new-girl-shared-universe-taylor-swift-plothole/