Shinsadong Tiger
Initially, it was reported that DIA would make a comeback on November 7, 2018, with a "Bo Peep Bo Peep 2.0" produced by Shinsadong Tiger. However, nothing materialized. On February 20, MBK Entertainment confirmed both DIA's comeback and the single's production being handled by Shinsadong Tiger and marks their first release as seven members without Jenny due to a knee injury. On March 19, 2019, DIA released their fifth EP titled "Newtro" alongside its title track "Woowa", after previous reports of a release on March 28 and 21. On July 6, 2019, MBK Entertainment confirmed that Jenny left the group due to health problems with her knee.