V, like the other six members of the band, follows only his bandmates' and their band's official accounts. They each have about 20 million or more followers within three days of joining Instagram.
However, eagle-eyed fans noticed that V, 25, had followed K-pop girl group Blackpink's Jennie, 25.
Even though he quickly unfollowed her - he said he had clicked on a recommendation from Instagram by mistake - the damage was done.
Fans began bombarding Jennie's comments section, asking if they were dating, accusing her of riding on BTS' popularity and posting hateful remarks, such as "Don't get your hopes up, you roach" and "Leave V alone".
Others left strings of nasty emojis, such as vomiting, coffins and poop, even though she had done nothing.
Jennie was rumoured to be dating G-Dragon from BigBang in February, although the romance was never confirmed.
The social media drama did not end there, as Blackpink fans retaliated on V's Twitter account, making comments about his beloved grandmother, who died in 2016.
One fan wrote: "That's why yo grandma dead. Leave Jennie alone." Others called him creepy and a stalker.
A few other members of BTS also ran into minor hiccups as they learnt to navigate the app.
Jin seemed confused about the "like" button, asking on fan app Weverse: "But why do you press 'like' on Instagram? Does it mean 'I like your writing/post'?"
Suga accidentally left the comments section of his first post open, which he later fixed. Both Suga, 28, and Jin, 29, said that Instagram was "hard".
Jimin, 26, struggled with the app too and admitted: "I would be better if I had used social media more before."
Meanwhile, Jungkook, 24, was trying to figure out the difference between posting to his grid and Instagram Stories.
For RM and J-Hope, both 27, it has been smooth sailing and they have been sharing snippets of their lives without stirring up any social media controversies. – The Straits Times/Asia News Network