Playing to 15,000 fans all by his lonesome self in a modernized arena was one thing. But trying to commandeer a crowd of 50,000 people with just an acoustic guitar, a loop recording machine and his undeniable personal charm in the most gargantuan and echoey room in Minneapolis?

U.S. Bank Stadium was simply too much for Ed Sheeran. His sold-out concert Saturday night at the Vikings’ new mega-sized, ultra-problematic home at once felt way too big and surprisingly flimsy.

What is with this dude and his aversion to working with other musicians? Sheeran, 27, must now be the second-richest red-bearded millennial in England after Prince Harry, so it’s not like he can’t afford to hire a backing unit, even if just for less than half his set.

Granted, his one-man-band shtick — wherein he records his vocals and guitar parts and triggers them into a repetitive loop to sound like a full ensemble — seemed sort of nifty when he first came to town in 2012 at the State Theatre to serve as an opening act for Snow Patrol, the Irish band he paid back by recruiting them to open Saturday’s concert. His solitary stage gimmick even still carried him through his fun Xcel Energy Center set in July 2017.

Sheeran’s act is really starting to wear thin, though. It didn’t help that he had the same looming video production with him Saturday as at the prior X show, and he played very nearly the same set list. Once again, the urgent heart-tugger “Castle on the Hill” opened the show, the cornily horny megahit “Shape of You” kicked off the encore, and in between he held himself up as possibly the worst rapper of all time in “Eraser.”

Even less helpful was the fact that Sheeran’s team chose USBS as his stadium locally. Just the vastness of the high-ceilinged venue seemed counterintuitive to his act, but so did its notoriously problematic acoustics.

After a string of better-sounding appearances there — including the Beyonce/Jay-Z twofer and his old pal Taylor Swift’s two-nighter — the $1 billion NFL-branded facility once again cut concertgoers short.

Anytime Sheeran slapped out a beatnik-funky drum beat on his guitar and put it on repeat, such as “New Man” or the pre-encore finale “Sing,” it sounded hopelessly mucky and un-funky, sort of like a kitchen-sink garbage disposal trying to clear out gallons of half-dried concrete. And whenever he piled on his vocals in layered harmonies, as in “Bloodstream,” they bounced around the room like a superball.

Whether an actual band would’ve helped with the sound problems — Snow Patrol’s downcast, swirling hits “Run” and “Chasing Cars” sounded pretty good earlier — a backing ensemble might have at least warded off some of the lulls in energy throughout the show.

There were moments in Saturday’s concert when a USBS crowd hasn’t looked so sullen and detached since the Vikings’ 34-6 loss to the Colts in 2016. Those languid parts were never when he was playing his mellowest, mushiest tunes, either, but more in his breathy and passionate rockers such as during the mash-up of “Feeling Good” and “I See Fire.”

There was a Bizarro World situation happening Saturday, wherein Sheeran’s softer, quieter songs were the ones that really got the crowd amped up, including “Dive” early on (a non-hit highlight from last year’s album, “Divide”) and “Thinking Out Loud,” “Photograph” and “Perfect” later on (three of his biggest singles). If he ever were to add a band, those acoustic favorites should probably stay as-is.

As if trying to better connect with the larger crowd, Sheeran talked more than usual, but his usual, humble, self-deprecating wit almost sounded desperate. He went on a long spiel early in the set urging the fans to get up and dance often. He later addressed the men in the crowd whom he guessed were there begrudgingly with their girlfriends or daughters, upselling them on the fact that their restroom lines were guaranteed to be short.

More wasn’t merrier Saturday, not for Sheeran nor his crowd. While marveling at the audience size early in the show, the singer actually bragged that he’s “played these same exact songs to two people in a bar somewhere.” Maybe it’s time he tailor his songs to fit the places he’s playing today.