pertinacious
/ˌpər-tə-ˈnā-shəs/
adjective
adhering resolutely to an opinion, purpose, or design
perversely persistent
stubbornly tenacious
/ˌpər-tə-ˈnā-shəs/
adhering resolutely to an opinion, purpose, or design
perversely persistent
stubbornly tenacious