Nah actually its pretty simple. The issue is that the show is pretty nonlinear so they don’t clue you into how much time has passed.
Van has been in love with Earn since season 1. Its no secret. Earn loves Van too but has always sabotaged the relationship (we now know why) Van came to Europe as much for Earn and she did herself. Now that we’re in Season 4 and Earn has been going to therapy (again in a time skip that only suggests he’s been going for awhile) he’s taking positive steps towards a progressive, mutual, loving relationship with Van. The series always pretty much spelled out that once Earn got his shyt together he and Van would be together. In season 3 he got his financial shyt together. Now in season 4 he’s getting his emotional shyt together.