Miami Dolphins owner Stephen Ross doesn’t seem able to win these days, even on a small deal. In the wake of a proposed $350 million renovation of Sun Life Stadium’s failure to make it to a vote in the Florida House last week, developer Ross just sold a condo he owned in a waterfront property built in West Palm Beach by his Related Group — at a steep loss. According to real estate records, Ross, 72, just sold a two-bedroom, two-bathroom condo on the sixth floor of The Slade, a building marketed as one of the city’s hippest. Ross bought the 1,725-square-foot digs in 2006 for $332,000, according to Palm Beach County records, and sold it a fellow New Yorker for $152,000. That’s a $180,000 loss, and $40,000 less than his asking price. To be sure, with an estimated $4.4 billion to his name, Ross is not going broke. He is, after all, No. 86 on the Forbes list of the 400 richest Americans. But what does it say about the condo his company built, a $63 million, yellow-and-red tower designed to be cutting-edge and likely to rejuvenate the city’s north end? When workers broke ground, Miami-based builder Jorge Pérez, Ross’ partner, touted the towers as where he’d chose to live if he could. Ross hasn’t responded to a request for comment.