On a quiet weekend in movie theaters, Lionsgate’s “Den of Thieves 2: Pantera” debuted atop the box office with $15.5 million.

The theory has been circulating ever since the first season aired, but several members of the cast say that it's wrong.

Pantera” opened at the top of the box office this weekend, grossing $15.5 million to lead all films in North America, according to industry estimates released Sunday. Lionsgate’s sequel to the 2018 ...