Matthew 5:11. Count them:
1. Blessed are the poor in spirit,
2. Blessed are those who mourn,
3. Blessed are the meek,
4. Blessed are those who hunger and thirst . .
5. Blessed are the merciful,
6. Blessed are the pure in heart,
7. Blessed are the peacemakers,
8. Blessed are those who are persecuted for righteousness . 9. Blessed are you when they revile and persecute you, . .
I see what you are saying. No biblical scholar here, but I am assuming we count 8 Beatitudes because in those Jesus is talking about various groups, but, then, in what you are calling the 9th, he is addressing his followers to tell them that they shall be blessed, also, when others persecute them.