django and character set

Hi, everyone. When deleting data from django, in the column in Korean,

(1366, "Incorrect string value: '\\xED\\x85\\x8C\\xEC\\x8A\\xA4...' for column 'object_repr' at row 1")

An error occurs. Mysql's DB and column character set are utf8mb4. I also set up 'OPTIONS': {'charset': 'utf8mb4'},

There is no problem when saving it, but there is only a problem when deleting it.

I'm asking you a question because I can't solve it even if I google it ^{^}