DIA's Jenny has been missing from the public eye and group activities since early December with no word from MBK Entertainment or the other members, and fans are worried. Her last Instagram post was on Dec. 5th. DIA have appeared as a group without Jenny numerous times since then, including a bit on "The Return of Superman", a recent photo op with rookie group ZGirls, and a guest appearance at Hwang Chi Yeol's concert on Dec. 29th.
MBK have also failed to deliver on a promised November comeback for DIA, and have not made any kind of statement about that either. Given the departure of Eunjin from the group last year, some fans suspect that Jenny may be leaving the group and MBK is delaying the reveal. The tag #MBK우리는다이아몬드를원니다 (op's translation attempt: "MBK, we want our DIAmond") is being circulated on Twitter as fans attempt to get a response from MBK.
Source: Instagram: s0yul96, theqoo.net