name another series with 4 duds in a row
duds meaning they were/still are* considered a disappointment critically and just general audience opinion but weren't necessarily flops at the box office but in most cases will have underperformed.
(*of course some may since been reappraised as being ahead of their time)
Alien (A3, AR, Prometheus, Covenant - not including AvPs)
Predator (AvPx2, Predators, The Predator)