Simply null and void: Chaos.
HR canceled first accepted appointment (Thur), asked to select 3 more videocall slots the following week, never showed up nor called (Mon), rescheduled (Wed) then postponed again. Simply by sending me GoogleMeet invites, never a mere email, sms, nor courtesy call prior or after the accepted/canceled slot.
Granting them benefit of the doubt, connected to the ultimate meet they offered, got stood up again, w/o any explanation nor response to my several emails. No phone number displayed in the HR's email signature either.