@Elliander --
It's possible for a person to be your tax dependent and yet not be a "qualifying person" for purposes of filing HOH. See the table on page 10 of IRS Publication 501. Also see the definition of Qualifying Child under "Relationship Test" on page 12.
2022 Publication 501 (irs.gov)
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
