Actor Kai Ko, the mournful star of Un Certain Regard film “Moneyboys,” declined to jump the queue for vaccinations in his native Taiwan, and so couldn’t walk the red carpet in person at Cannes this year.

Nevertheless, his performance in first-time director C.B. Yi’s exploration of Chinese hustlers balancing the pressures of love, family and financial stability has cemented him as formidable talent to watch.

The film will likely prove a helpful boost to his now decade-long career, which was derailed despite a rapid rise after an infamous 2014 marijuana bust in Beijing alongside Jackie Chan’s son Jaycee Chan.

Ko points out that he never intended his subsequent break with entertainment world to last. “I never left! I took a break for a while, but I don’t know why people keep using the phrase ‘comeback,’” he said. Taiwan is too small a market for actors to create opportunities to spearhead their own projects, he explained, so there was a period when he was out of work, waiting for new prospects. “It was an image problem. When I had a bad image, nobody came knocking, but after a while, when producers got a little bolder, they came looking for me again.”

Ko came to fame while still a student thanks to a leading role in the 2011 coming-of-age high school romance “You Are the Apple of My Eye,” which netted him a Golden Horse Award for best new performer.

He then rode the wave of the slick Chinese blockbuster “Gossip Girl”-like series “Tiny Times,” appearing in three of the franchise’s four films in 2013 and 2014, making him a well-known name in the larger mainland market.

But the same week Chinese authorities issued a new directive banning entertainers engaged in drugs or prostitution, he was arrested on drug charges, making him a convenient, high-profile example of Beijing’s new hardline stance.

Chinese officialdom chastised his negative impact on the country’s “social morality” and held him in detection for 14 days. While there, he delivered a tearful apology to fans via state broadcaster CCTV similar in style to forced confessions frequently employed by Beijing.

Censors cut out his scenes in the landmark Chinese blockbuster “Monster Hunt” and forthcoming “Tiny Times 4,” and his advertisement deals and his variety show engagements were cancelled. His film set to release at the end of that year, the superhero romantic drama “A Choo,” was indefinitely postponed.

In the past eight years, Ko appeared in only one arthouse project, Midi Z’s 2016 “The Road to Mandalay,” and a brief cameo in the 2017 Taiwanese horror mockumentary “Mon Mon Mon Monsters.” After six years on the shelf, “A Choo” was finally released in Taiwan last summer amidst the pandemic, after Ko’s father reportedly bought the rights to distribute it himself for more than $2.5 million.

Looking back at the drug bust, Ko feels remorse, but also that he’s made the best of the path it’s set him on.

“I broke the law, so I really am sorry to a lot of people for that and all the people who were affected. But in terms of my career, I think everything happens to a person for a reason, and if something happens, you just do your best to move forward,” he said.

His anchoring portrayal in “The Road to Mandalay” of an illegal immigrant in Bangkok was well-reviewed, and inspired “Moneyboys” director Yi to give him the lead role in the Un Certain Regard film.

Yi had long, one-on-one conversations with top candidates for the part over the course of two years, but honed in on Ko from the moment they met. “When I’m casting, I think a lot about an actor’s voice, almost more than their faces. Kai Ko’s voice had a quality to it that got stuck in your head,” he said.

Yi praised Ko’s steadiness, particularly while the team was shooting scenes of gay sex.

“I never needed to advise him on anything; he just knew what to do. I was a bit stressed at first about how it would go, but he was so professional that I thought, if he’s not nervous, why should I be?” he said. “I think he likes to work on subtle, emotional roles.”

Ko is slightly more interested these days in commercial films, since he puts less of himself into them and they take less of an emotional toll. But he was drawn to the subject of “Moneyboys,” as well as the challenge of immersing himself in the mindset of his complicated hustler character, Fei.

The hardest part of the role having to kiss so many different people in quick succession while trying to turn each encounter into an opportunity for expression.

“You can’t shoot a film chronologically from start to finish, so in one day, I’d sometimes have to kiss seven different men. Some I kissed for a day, others less than an hour. Some used a lot of tongue, others didn’t. I tried to find ways to make kisses with customers different from those with [Fei’s romantic partners] Long and Xiaolai, which had to be infused with a lot of emotion,” he said. “It was interesting — I’ve never shot scenes in that way, nor so many kisses, not even with women.”

Ko now has four film projects waiting in the wings for release, all postponed by COVID-19. Reflecting on how his 2014 tumble shaped his career from the vantage point of his Cannes appearance, he brushes away his regrets.

“If I had continued to have a lot of work, I probably wouldn’t have had encountered this sort of opportunity. Now, looking back, I think I just need to do what I can to live my best, most full life — and to prove to everyone that I still have what it takes to act.”