wrongheaded

/R AO1 NG HH EH0 D IH0 D/
adjective
  1. 1

    Having an obstinately (persistently, stubbornly) perverse/erroneous opinion or judgement.

    โ€œHe's not just wrong, but wrongheaded, about raising the kids.โ€

Source: https://en.wiktionary.org/wiki/wrongheaded