Your second URL is probaby incorrect, because
+ in a URL is decoded to a space character. You need to encode that
%2B instead, so it'll be treated as a literal
+, not a space character.
Since it's being mangled to space character, your query string will NEVER match, because you'll be comparing:
database: ... Grade I, 3 yr old+, 8F ... query : ... Grade I, 3 yr old , 8F ... ^---note the space