Hi @belkisrondonp - thanks for using the service :)
The payout depends on Hive price - it was 50/50 when you take into account that Hive is around $0.4 and HBD is around $1 :) This is how it works on hive blockchain in general and you would get the same payout also if you wouldn't use @reward.app (of course Hive would be paid as Hive Power).