Luna's latest social media post is concerning fans.

On May 1, Luna shared on Instagram, "Don't make promises you can't keep. Please."

Fans assume the post regards an issue with f(x)'s comeback. The girl group has been on a hiatus since the album '4 Walls' in 2016. Recently, Luna told fans to not worry about f(x) as they will be greeting fans soon. However, the concerns are ongoing.

Fans commented, "What's going on? :(", "Who broke your promise?? Don't be upset", "Remember we are always on your side."