Owning a home may not be in the cards for many millennials

>"It's a bit of a mystery why this is happening,"

Not really. Most of the people I know in that age group, including myself are too poor to even think of buying a home now or in the near future. I personally haven't moved in 7 years because if I do my rent will jump from $1200 a month to something closer to $2000 for something similar where I live now. These days in my city $1200 will be lucky to get you a bachelor suite. I'm just lucky my rent's never been raised since I moved in.