Did you enter a qualifying person as a dependent?
See this TurboTax support FAQ for head of household - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-filing-status/qualify-head-household...
See this TurboTax support FAQ for qualifying person - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-filing-status/qualifying-person-head...
