Results inconsistent while using UTF-8 comparison

spray_cleaned2 := join(incoming,spray_cleaned2 := join(incoming,                        lookups,                            trim(left.username[std.uni.find(left.username,u8'@',1)+1..]) = trim(right.username), transform({utf8 username,  boolean is_user_internal,  utf8 domainonly,  utf8 leftusername,  utf8 rightusername}, self.is_user_internal := if(trim(left.username[std.uni.find(left.username,u8'@', 1)+1..]) = trim(right.username), true, false);                                self.domainonly := left.username[std.uni.find(left.username,u8'@', 1)+1..]; self.rightusername := right.username; self.leftusername := left.username; self := left; ), left outer, lookup);

Issue I believe is on the "Bold" faced IF 

Works when this assignment self.rightusername := right.username is changed to
self.rightusername := trim(right.username);;