C# - Clause Is Used Inside Linq Statement Produces Different Results Than When Used Outside?

I have the following statement:

List<string> tracks = new List<string> { "ABC", "DEF" };
var items = (from i in Agenda.AgendaSessions
select i).Where(p => p.Tracks.Any(s => tracks.Contains(s.Code)));

this returns all sessions which track contains either ABC or DEF, now when I rewrite the statement like the following, it returns All sessions regardless, as if the clause always yeilds into true,

var items = from i in Agenda.AgendaSessions
where i.Tracks.Any(s=> tracks.Contains(s.Code))
select i;

Update

if there are other clauses within the where, does that affect the results?