It takes a certain amount of resilience to be a Katseye fan. Since debuting three years ago via the boot camp meets reality TV show The Debut: Dream Academy, the multinational K-pop hybrid girl band have put their so-called Eyekons through the wringer. Last month alone they lost their second member to a “personal health and wellness” related hiatus, with Sophia joining Manon (who stepped away in more mysterious circumstances back in February) on the sidelines. Weeks later, they landed their first US No 1 album with Wild, a collection led by the carbonated dance-pop rocket Pinky Up – a song referred to by the band’s many online detractors as “skibidi toilet music” (ie slop).

Even as this debut arena tour arrived in the UK, there were fears the newly reshaped quartet might be reduced to a trio after Megan sprained her ankle. But if the fans are worried, they don’t show it, their ear-piercing screams drowning out the opening Hootie Frutti, a sonic melange that somehow makes Brazilian funk sound leaden. By the time petulant hyperpop bop Internet Girl kicks in they’re screaming lines like “eat zucchini, eat zucchini” as if their lives depend on it.

Ear-piercing screams … Katseye at the O2 Arena

A now healed Megan, Lara, Daniela and Yoonchae do their best to reward the enthusiasm. They lock into the featherlight early single Touch, which recalls their K-pop peers NewJeans, while last year’s breakthrough single, Gabriela, is given a delicious flamenco makeover. The choreography is frenetic throughout, aided by 10 dancers, but the minimalist staging – just a raised platform and a short runway – means the focus is very much on the songs themselves. That causes problems when the best they can muster is Animal, a flaccid Ed Sheeran co-write, or My Way, a song so dated it’s essentially a refried X Factor winner’s single.

Things pick up when the band are allowed to unshackle themselves from the rigid choreography. The strutting new-wave of Bel Air – a resuscitated Charli xcx demo from 2013 – offers up flashes of their individual personalities, while a chest-rattling Gnarly, complete with its “I’m the shit” hook, shows how well they can sell ludicrous bangers as long as they stay just the right side of goofy. Not that the fans care a jot; to them, Katseye can do no wrong and the skibidi toilet music is simply part of the charm.