Flirted with multiple people but only 1 relationship flag

Not sure if this is a bug or functioning as intended. I have flirted with Emmrich, Lucanis, and Darvin. At first, all three had the heart relationship flag in their companion profile but now only Emmrich does. I've been assured by my friends who are further in the game than I am that I haven't screwed up any potential relationships but the flags not showing up is bothersome. Is this functioning as intended or is something missing? Thanks!