On November 29, 2016, Happyface Entertainment announced that MINX would re-debut with a new name and the addition of two new members.
2017: Debut with Dreamcatcher, MIXNINE
On January 13, 2017, the reformulation of the group, known now as Dreamcatcher, made its official debut with the single "Nightmare".
In October 2017, she, alongside fellow members JiU, Yoohyeon, and Dami, became contestants on the survival show MIXNINE. However, on December 10, 2017, it was announced that all four members would leave the show.
On September 13, she became a contestant on the vocal reality survival show V-1. She managed to make it to the final round, but lost to WJSN's Yeonjung.
On January 22, Dreamcatcher Company revealed that Siyeon would release her first solo single, "Paradise", on the 29th, ahead of the group's comeback.