Gunna’s first major feature appearance came early in his career, when Young Thug plucked the Atlanta rapper out of relative obscurity and placed him on “Floyd Mayweather,” a highlight of his 2016 event album JEFFERY. Memorable as that song was, though, it was easy to miss Gunna’s contributions, and not only because it cast him against Gucci Mane and Travis Scott. Many casual listeners initially assumed his performance was part of Thug’s, since their voices, flows, and styles overlapped so seamlessly that fairly close attention was required to tell where one ended and the other began. It’s no mystery what Thug, who signed Gunna to his YSL label, heard in the young rapper: himself.

These days, there’s no mistaking the two. While Young Thug’s voice has continued to evolve into ever wilder forms over the last two years, Gunna still sounds more or less like the same subdued echo of his boss that he did in 2016. Where Thug thrives on constant invention, pushing against even the currents that he helped create, Gunna is a weather vane content to ride the wind—a perfectly proficient rapper with a fairly conservative variation of the singy murmur that’s proliferated in Atlanta rap since Future’s ascent. On Drip Season 3, the latest installment of Gunna’s flagship mixtape series, he locks in on a vibe and rolls with it wherever it goes. Usually it doesn’t go too far.

Young Thug shows up twice, and in those two appearances he shows nearly as much range as Gunna does on the entire tape, applying his tactile rasp to “King Kong” and yelping out an R.I.P. to Hugh Hefner (“He like my daddy!”) on “Oh Okay.” Welcome as his contributions are, the title of that last track inadvertently sums up the muted response almost every song on Drip Season 3 provokes, these two included. Given Thug’s track record with songs about legendary primates, “King Kong” in particular feels like a missed opportunity. The title promises a tower-scaling beast of a song, but instead the beat is glum and the performances are weary. It should be so much more fun than this.

Drip Season 3 is filled with moments like that, finished tracks that fail to make good on the promise of their ingredients. For his part, Gunna is a capable rapper, and he peppers his free-associative lyrics with enough flashes of wit and randomness to suggest maybe he could grow into something more. “Working like Gotti, my crew almighty/No TGI Fridays, eat five-star, we dining,” he raps on “Almighty.” He’s got top-tier producers in his corner, too, including Metro Boomin, Turbo, and Wheezy. But there’s no spark in many of these songs, and Gunna isn’t a dynamic enough rapper to anchor a 52-minute project. By the time the tape reaches its nadir on “Mistress,” a romanceless “Penthouse Forum” boast with a numbing chorus (“Baby got big titties/...Squirt a lot of water out her kitty”), he feels like a pitching prospect trying to fake his way through the order a second time with just one pitch.

We’ve already seen proof that Gunna can make his modest range work for him. With last year’s unusually serene Drip Season 2, he created an aching, emotive mood piece that was genuinely moving at times. A talented rapper could build on that sound. But Drip Season 3 is a reversion toward anonymity, toughing up its presentation just enough to destroy the allure of its predecessor, but not so much that it actually bangs. It’d be unfair to expect Gunna to keep pace with his mentor’s iconoclastic drive, but you’d think that a guy who came up under Young Thug would understand the last place you ever want to position yourself is in the middle of the road.