애증(love-hate relationship) 결핍(Lack)
Lack of love could be a translation
But really it is something like Lack of Love and Hate. Or lack of love-hate relationship.
French has is as “Sans Amour et Sans Haine”
Which means “without love and without hate”.
Japanese has it as “ 愛憎不足” which is lack of love and hate.
Seoil does talk about the title on Twitter. It is the love-hate relationship cause by a misunderstanding.
Also, Hangyum at the wrong time in chapter 40 said everything but he overheard Hajin say it. He talks vague but he does communicate. This will show in the next chapter as well. Does not help that Hajin appears to be too dense. We see they are not communicating but they don’t realize there are issues. They don’t communicate because they don’t realize the issues. If they don’t know something is wrong the can’t properly communicate.

the 76284th attempt of a petition to change the name to lack of communication