I have no problems loading hands from FT and PS into PT3. My FT account is the primary user name in PT3, but when I add the PS alias it only adds hands previously loaded. If I continue to play on PS and import more hands, these hands only show up in stats for opponents and seem to not exist for my PT3 primary name. If I go back and remove PS alias, then re-add it, the stats show fine.
There seems to be a bug in connecting newly imported alias hand data.