In the years since Hollywood “discovered” autism, the tendency has been for movies to treat those carrying this burden as more “Rain Man” quirky and cute than “Rain Man” challenging.

Symptoms and behaviors might come and go as the plot required. The burden for the caregivers and for the person trapped in autistic tics, coping mechanisms and manias would show up as the occasional “reminder” of the day-in/day-out difficulties facing those diagnosed or undiagnosed and their families.

But the ebullient autistic child in “The Unbreakable Boy” reminds us that this malady is a lot to deal with. Because he’s a LOT. Period.

Austin, aka “Auz Man” is a manic chatterbox who lives his waking hours at near full speed and top volume. All it takes is a mean and clever classmate to crack “I want the truth!” to send Auz Man on an uninterruptible run through the entire “You can’t HANDLE the truth” speech from “A Few Good Men.”

Class at his Oklahoma middle school? It might as well be dismissed until Austin is done — which could be never as he’s memorized this entire movie, among many others — or removed from their midsts.

“The Unbreakable Boy” is a manipulative weeper that doesn’t so much hurl one huge challenge/obstacle/setback/test or unpleasant revelation after another at the viewer, as gently introduce them for our entertainment.

Austin is born not just with autism, but with Osteogenesis Imperfecta, brittle bone disease. He’s a manic, uncontrollable child who demands constant attention lest he heedlessly break another bone.

Austin’s mother Teresa (ahem) (Meghann Fahy) had it. That’s not something she mentioned on the first, second or third dates with his pharmaceutical-rep Dad, Scott (Zachary Levi). No, she brought it up after she lets baby-daddy know she’s pregnant, and before he’s learned her last name. Or that she’s been married before. Twice.

That’s OK, because Scott is an alleged grown-ass man who never gave up his “invisible friend.” Now “Joe” (Drew Powell) is dad’s invisible drinking buddy.

There’s an Oklahoma joke in all that. But the movie is too cheerfully upbeat and bubbly to tell it and frankly too-invested in turning this kid into a life-affirming metaphor for boundless optimism, ignoring all obstacles and sugar-coating a whole lot of problems that come with a family this challenged.

The line between “uplifting” and “cringy”; is a narrow one here.

In writer-director Jon Gunn’s script, chatterbox Austin (Jacob Laval) narrates the story of his life, mostly in a flashback from “the day everything broke” as his alcoholic dad took one drunken drive with the kids (Gavin Warren plays Auz-Man’s younger brother Logan) too many.

The endless parade of medical problems facing Austin’s birth and the accidental family formed by this child (Patricia Heaton of “Everybody Loves Raymond” plays dad Scott’s mother) can only be surmounted by constant adjustments, constant stumbles, the occasional ultimatum, a smile and a homily.

“I wish I could enjoy anything the way my son enjoys EVERYthing!”

There’s a faith-based subtext clumsily and half-heartedly grafted onto the story (Peter Facinelli plays a pastor who’s had his “challenges”). And the “true story” anchoring all this doesn’t tidy up the logic or unreality of it all. A tiny but telling example — there’s a father-son church group campout coming up. Scott drives a Toyota Land Cruiser, with roof rack, snorkel and front bumper towing wench. Scott lives in Oklahoma. But Scott tells us “I HATE camping!”

At least the kid is gratingly bubbly, if a tad insufferable.

Yes, writer-director Gunn gave us “Like Dandelion Dust,” a Mira Sorvino faith-based film of endless “trials” — including alcoholism.

And yes, MAGA star Zachary Levi took credit for keeping this “What, me worry?” pollyannaish motion picture from theaters in 2022, when it was set to be released, hoping for an America more ready to “Don’t worry, be happy” its way to theaters after a democracy-breaking Trump re-election.

It didn’t pay off. But perhaps this won’t the career killer it looks like. Somebody has to replace Kevin Sorbo and Kirk Cameron, after all.

Rating: PG, alcohol abuse, bullying, profanity

Cast: Zachary Levi, Meghann Fahy, Jacob Laval, Gavin Warren, Drew Powell and Patricia Heaton.

Credits: Scripted and directed by Jon Gunn, based on a book by Scott LeRette and Susy Flory. A Lionsgate release.

Running time: 1:49