It seems that KARD's B.M has suffered a minor neck injury.
On October 4, one affiliate from KARD's ongoing 'Wild Kard Tour Part 2' posted a video on Instagram, writing, "That moment when @j.seph_ needs to fill in for @bigmatthewww during the #monsterdance break bc of a neck injury... and when you cant stop staring... like watching a disaster happen right in front of you but youre laughing instead... #kard#jseph#bm#argentina."
According to the Instagram post, fellow KARD member J.seph will be filling in for a dance number in B.M's stead, due to B.M's neck injury. Still, it seems B.M will still be able to perform for fans during the South America leg of their tour, and he can be seen cheering J.seph on in the brief SNS clip.
Hopefully it's nothing too serious!