Plans by HBO’s new parent company to launch a Netflix rival are coming under fire from insiders — many of whom are pointing the finger at their new boss, John Stankey.

Critics told The Post that AT&T’s plans to launch a new streaming service to compete with the likes of Netflix and Amazon are off to a rocky start — and have led to clashes between HBO staffers and Stankey, who heads AT&T’s new entertainment division, WarnerMedia.

“He thinks he knows a lot more about the business than he does,” one former HBO executive said of Stankey. “He is not a pleasant person to work around.”

Shortly after AT&T executives revealed plans were in the works for a new streaming service last November, HBO execs started peppering Stankey with questions, one former employee said.

“We’d say: ‘We don’t understand the plan. Tell us what you’re doing,’ ” a former HBO employee said, adding that HBO’s culture before AT&T acquired it was one of questioning.

Fed up with the questions, Stankey called in senior management and reamed them out, yelling: “I am sick of hearing this! I know more about television than any of you! Stop questioning me,” the employee said.

“He’s a screamer,” said another source who works with HBO. “He doesn’t have a good sense of what made the company so valuable.”

WarnerMedia went public with its new streaming plans in July, boasting that the service — called HBO Max — will come with 10,000 hours of premium content when it launches in 2020. Shows will include The CW’s “The Fresh Prince of Bel Air,” HBO’s “Big Little Lies,” and “Friends,” which AT&T bought the rights to for $425 million — outbidding Netflix.

HBO staffers say the problems started when they got their first whiff of the streaming plan back in November at a meeting for AT&T execs to roll out their vision for WarnerMedia to analysts and media.

According to an insider with knowledge of the meeting, WarnerMedia execs, including HBO, were “blindsided” by the streaming plans, which included a three-tiered pricing system that insiders then panned as overly complicated.

Months later, AT&T said it would have two price tiers, and most recently, in July, it moved to one flat price.

Stankey, a longtime telecom exec who has been with AT&T since 2005, defended his management style against critics in a recent interview with Variety by describing himself as a “fairly direct” person. “I’m not one who minces a lot of words.”

A source close to Stankey added that he has been holding meetings and taking questions from senior WarnerMedia executives in order to clarify his streaming strategy.

But critics say his harsh tactics have prompted talent — especially female staffers — to start looking for work elsewhere.

“He doesn’t understand that the value of HBO is linked to its people,” a former employee noted, citing an internal meeting in March in which the exec offended the division’s women staffers.

The March meeting came one month after AT&T’s $85 billion deal to acquire Time Warner, announced in 2017, was OK’d by the courts, allowing AT&T and Stankey to make major management changes.

HBO employees were gathered to meet the new management team, including Bob Greenblatt, the former NBCUniversal chair who was tapped to head HBO, TNT, TBS and HBO Max.

One staffer asked if she could ask two questions, to which Stankey snapped, “You get one!,” the source said. The staffer then proceeded to ask why none of the top execs under Stankey’s WarnerMedia were women.

Stankey replied that there were no women on his team because there is “no bench strength” at WarnerMedia, this person said. The “dismissive answer” did not take into account top execs, including Bernadette Aulestia, the global distribution chief; Eve Konstan, the general counsel; and Marisa Famulare, the chief financial officer, the source said. It also didn’t account for Turner ad sales veteran Donna Speciale, who left the company earlier this month — and who was “frustrated” by the male-dominated culture there, sources told The Post.

Days after his remarks, one of Stankey’s chiefs, Warner Bros. chief executive Kevin Tsujihara, stepped down over texts showing he had an inappropriate relationship with an actress.

Stankey supporters note that he replaced Tsujihara with Ann Sarnoff, a former president of BBC Studios America, who is now the first woman to run Warner Bros. They also point to other female execs who report to Stankey, including Priya Dogra, whom he promoted to executive vice president of strategy and corporate development, and Christy Haubegger, whom he hired as chief enterprise inclusion officer.

“Regarding women in leadership positions, we’ve made significant progress in the last 12 months across the company and we’re committed to continuing to do so,” a WarnerMedia spokesperson said.

The company declined to comment otherwise for this story.