Deadline.com and others have been predicting an almost healthy second weekend for “Captain America: Brave New World.”

And “awareness” was so high on Neon’s hyped-to-high-heavens horror tale from Stephen King, “The Monkey,” that “the sky’s the limit” predictions rattled out this week.

But both are seriously underperforming earlier Feb. 21-23 weekend expectations.

“Captain America” was projected to clear $30 million on its second weekend. Easily. And that would have had some quasiness to it, considering it cleared $88.8 million on its Valentine’s Weekend Opening.

But a $3 million or so Thursday turned into a $7.5 million Friday. That led to a $28 million “win” on its second weekend. That’s almost a 70% plummet.

What do we call that “phenomenon”over 70% drop,” kids? That’s “A Tyler Perry Plunge,” named for the once-and-always-Madea, whose movies always took a nose dive on their second weekend.

It may clear slightly more than $25, but say a $7.5. Friday and a $10-12 Sat., with $5 Sunday and it’ll be lucky to get there. And in any event, that steep a drop is a sign that a picture’s appeal is front-loaded, that most everyone who wanted to see it caught it opening weekend, that they’re not going back and that they’re not talking it up (word-of-mouth) to their friends.

Yes, Anthony Mackie, Giancarlo Esposito and Harry Ford are a fine cast to hang this on. No, it’s not “diversity” that’s hurting it. The humorless, rewritten and reshot “Brave New World” is just not very good, and plays as kind of a bummer, which explains the steep decline.

If it bests $25, at least it won’t set the “Marvel Movie Second Weekend Disaster” record that “The Marvels” currently owns. That one fell off 79% on its second outing.

Marvel movies are critic proof, and while less discerning reviewers, and younger and sometimes gutless ones, are reluctant to criticize a movie that’s sure to be a hit, the audience for this one is moving on — in a hurry.

Horror also used to be a critic-proof genre, with even the cheesiest cheese dogs with frights and gore built in sure to open in the low $teens and sequels in popular franchises opening in the $20s.

And Stephen King’s his own horror industry.

“The Monkey,” whose trailer (Deadline.com reported) has been viewed over 100 million times, should waltz to an epic opening weekend.

But a $5 million Friday suggests “The Monkey” will hit $14, maybe a little more, perhaps a bit less. Neon, the distributor, did a lot better with “Longlegs.”

Was anybody actually “sold” by that trailer?

Like “Nosferatu” and for that matter “Longlegs,” “Monkey” is a tale you’re sure you’ve seen before — a “demonic” doll/toy, etc. But unlike “Nosferatu,” it’s artless and heartless. Unlike “Longlegs” there’s no Nic Cage.

It’s a pitiless story of random slaughter on a vast scale, all coming from twin little boys (Christian Convery) winding up that toy absent Daddy (Adam Scott) gave them long ago, with the boys growing up to be Theo James.

It’s meant to be funny and frankly it isn’t. One twin is wracked by guilt, the other bent on revenge. Yeah, a mother shrieking as she runs, pushing a flaming baby carriage, will amuse some. But come on. I doubt if anybody’s cackling at a random airliner dropping from the sky.

“Paddington in Peru” will pull in another $6 million or so, underwhelming for a lightly charming “Third time’s not quite as charming as the first two” kids film. That’ll give it a third place finish.

“Dog Man” is headed for fourth (it should finish its run short of $100) and the Chinese animated blockbuster “Ne Zha 2” will crack the top five.

“The Unbreakable Boy” from the “Wonder” folks, another tale about a plucky disabled child who inspires others, is bombing. It will clear $2 million, not much more. Zachary Levi is box office poison.

As always, these numbers will shift a bit later Sat. and Sunday we’ll have a clearer picture of who earned what. I’ll update this as the weekend progresses.