LMAAAO she didn't even know about Yuna's feelings for her?? So you can't say she ignored them. Yuna did all she could do to hide them so when Dahye found out she was lesbian of and wasn't spending as much time with Yuna like before, she realized her feelings.
You can you hope that Dahye doesn't make Yuna leave Joy for her, but not that Dahye is the problem. No one is at fault

ohh please writernim, Dahye ignored Yunas feelings for so long and now Yuna already have Joy just make that work and don’t complicate things