EF6 with SQLite - not restoring lists - entity-framework

Question

I am using EF6 to read and write rules for some validation to an SQLite DB. Code First approach. I successfully wrote the rules out to DB. As I tried to read them now, the complex rules which contain child rules seem to have empty lists of child rules, despite database mirroring that correctly. What is wrong there?
The class hierarchy is:
abstract Rule - abstract class with "Validate" method.
abstract ComplexRule: Rule - a rule which can have child rules
SuperRule, OrRule, AndRule : ComplexRule implementations
BasicRule: Rule - direct implmentation which does some pattern matching.
The Table as written out in DB is so:
RuleId,Condition,Value,Mode,Discriminator,ComplexRule_RuleId
1,,,,SuperRule,
2,*USA*,*PATT1*,1,BasicRule,1
3,*CHN*,*PATT2*,1,BasicRule,1
Reading code looks like this:
using (var db = new RuleModel())
{
var q = db.Rules.OfType<SuperRule>).FirstOrDefault();
}
it results in a SuperRule which Children are empty. The db.Rules contains all 3 rules, but there's no association between BasicRule and SuperRule.
The RuleModel (DbContext) looks like this:
public class RuleModel : DbContext
{
public RuleModel() : base("name=RuleModel")
{
}
public virtual DbSet<Rule> Rules { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
var sqliteConnectionInitializer = new SqliteCreateDatabaseIfNotExists<RuleModel>(modelBuilder);
Database.SetInitializer(sqliteConnectionInitializer);
}
}
The Rules look like this:
public abstract class Rule
{
[Key]
public int RuleId { get; set; }
public abstract RuleResult Match(Mapping m);
}
public abstract class ComplexRule: Rule
{
public IList<Rule> ChildRules { set; get; }
public ComplexRule()
{
ChildRules = new List<Rule>();
}
}
public class OrRule : ComplexRule
{
public override RuleResult Match(Mapping m)
{
// Some logics
}
public OrRule() : base() { }
}
public class SuperRule: OrRule
{
public override RuleResult Match(Mapping m)
{
//some logics
}
public SuperRule() : base()
{
}
}
public class BasicRule : Rule
{
public string Condition { set; get; }
public string Value { set; get; }
public RuleMode Mode { set; get; }
public BasicRule(string condition, string value, RuleMode mode = RuleMode.MODE_ANYWHERE)
{
Condition = condition;
Value = value;
Mode = mode;
}
public BasicRule() { }
public override RuleResult Match(Mapping m)
{
// logics
}
}