Kate Upton’s career is still chugging along. She’s not all over the place like she was a few years ago in Vogue and on two consecutive SI: Swim covers. Kate appeared in a third Swim issue, but she was conspicuously missing for this year’s edition. What gives? I remember how refreshing Kate seemed as she barrelled to greater heights. She brashly claimed she could “bring back the supermodel.“ She conquered social media, which was a big reason for her sudden rise to fame. Remember how she danced the “Dougie” and went viral? That was a cute period, and she had fun. Lately, things have changed. Kate’s acting a little punchy in interviews. She’s lost her old enthusiasm.

Page Six ran a long article yesterday about Kate’s terrible attitude, which is supposedly ruining her career. The full article is an interesting read. Here’s a condensed version:

As Upton’s career ballooned, says more than one fashion insider who spoke to The Post on the condition of anonymity, so did her ego. She went from “innocent” to exhibiting diva-like behavior, insiders say.

“She became really unappreciative of her success,” says a fashion publicist who asked not to be named for professional reasons, commenting on her general behavior. “It totally went to her head. She didn’t understand that people had taken a chance on her.”

Another modeling-world veteran says Upton’s demands became ridiculous, including asking for photographer approval on shoots and refusing to be photographed with other models. “Even Kate Moss and Naomi Campbell embrace new models and shoot with them,” the second source says. “If you look at people with those long careers, they know how to give back.”

The secret sniping is the latest setback for Upton, 22, who’s also noticeably absent from the most recent Sports Illustrated Swimsuit issue.

“She really shook up the industry in terms of how quickly you could achieve the usual markers of success,” says Betty Sze, managing editor of industry site models.com. “What takes high-fashion models sometimes years or decades to get, like the Vogue cover, the name recognition, the cosmetics contract …. Kate was able to get all those in the space of two or so years.”

But Upton was convinced she made it to the top alone. “It’s weird that in the press they’ll be like, ‘Your biggest fight was with the industry and the designers,’ and I’m like, ‘No, my biggest fight was with my agents, trying to get them to sign me into the castings,’” she told British Vogue last June.

Her new agents are convinced she has legs as an actress. [But] one Hollywood agent who asked to remain anonymous says Upton’s turn on the silver screen didn’t make a splash.

“Kate is not even on our radar,” the agent says. “If she thinks she can make it as a movie star, she’s clearly believing her own hype. I don’t even remember her in The Other Woman, but pretty, buxom actresses are not exactly in short supply. Without any discernible talent, she will struggle to get taken seriously.”

[From Page Six]

There’s more juicy stuff in there. Page Six lists quotes from studio execs and critics who mock Kate’s acting skills and wooden delivery in commercials. They say the fashion industry is no longer impressed because she’s difficult, which caused her to lose an Express contract. Kate’s full of herself, photogs and mags find her difficult to work with, and so on. Insiders resent how she’s not a team player and now refuses to promote on social media.

Kate has achieved household name status, so she’ll be fine if she drops the new attitude right now. She’s a very good model and shows some versatility. I do have my doubts about her acting skills, but she’s still scoring gigs. Kate just booked a role in William H. Macy’s new directorial project. The film is a road trip sex comedy about two friends (Kate and Lea Michelle) who fight over the same dude during an airport layover. Hmm.

Photos courtesy of WENN