CAMBRIDGE DICTIONARY:

take against someone

to begin to dislike someone:

I think she took against me when I got the promotion she wanted.

MERRIAM WEBSTER DICTIONARY:

take against

British, somewhat old-fashioned

: to begin to dislike (someone or something)

They took against her for no apparent reason.

OXFORD DICTIONARY:

take against

 ​[no passive] (old-fashioned, British English) to start not liking somebody/something for no clear reason