Chris, an architectural intern falls for a mysterious woman named Samantha, but she seems to know a lot about him, maybe too much. Is he just overthinking or is there more to Samantha than meets the eye?

I feel this is more of a tagline, to get the audience interested. And I believe a logline shouldn't be a question (but the experts will have more to say).

It looks like all the comments posted in that thread before the site was highjacked have now disappeared.
The logline is too long, but does not give enough details.
I can't guess the type/genre of the movie from it. Is it a comedy, a romance, a drama, a psychological tearjerker, a thriller, a sci-Fi or horror movie?
Also logline must give Act I and the inciting incident and an overview of Act II, without revealing Act III. Here, we only have Act I, with no indication of a Act II.

Also in one of the vanished posts, somebody suggested that the reason why Sam knew so much of Chris past without Chris recognising him was because Sam used to be Chris best male friend but is now female after gender realignment operation. Was he correct or is the reason why Sam know so much of Chris much more mundane: bunny boiler cyber stalker, telepath ?

Traditionally, lead characters are pro-active. What is the lead characters goal in your story? What must he do?