How to say leaving a fandom in Korean
Korean: 탈덕[ tal-deok ]

Meaning
탈덕 means leaving a fandom or stopping your support for someone or something you used to love. People often use it for idols, singers, actors, or characters when they are not a fan anymore. It is casual slang, so you will hear it more with friends and online than in formal situations.
Example sentences
나는 그 가수 탈덕했어.
I stopped being a fan of that singer.
친구가 왜 탈덕했냐고 물었어.
My friend asked why I left the fandom.
나 탈덕해서 이제 굿즈 안 사.
I stopped being a fan, so I don't buy merchandise anymore.
부산 콘서트도 갔지만 지금은 탈덕했어.
I even went to the Busan concert, but now I'm not a fan anymore.

