What is the meaning of にこだわる?

Question

英語での記載にこだわる理由は何でしょうか？
今まで通り(日本語で)に記載して頂きたいです。

I have no idea what にこだわる means here.

The nuance is once day, my Japanese translator who suddenly switched to English (instead of Japanese like normal) to translate a question, and she submitted it to the Japanese client.

After that, I received above feedback from my client. My translator told me that the question was a little bit tricky to translate to Japanese, so she decided to go with English. It seems like the client was not happy with English there, so I guess the にこだわる means something like get stuck, doesn't it?

Answer 1

While there is an argument to be made that this question can be answered by a dictionary lookup (as provided by macraf), I think that こだわる can be a little bit tricky sometimes and so this warrants an answer.

こだわる can mean things across a fairly wide range of English words. Jisho provides a decent definition, although as always the monolingual dictionary has more info. Very broadly, it typically has to do with having a strong preference or concern in a way that is unexpected. It can be unexpected because it's just not something most people care about that much, unexpected because the actual preference is unusual, or both.

For example

細かいことにこだわる

describes being nitpicky about small details, or as Jisho aptly translates it "splitting hairs". It can also express explicit choices motivated by unusual preferences as above, which is what's happening in your case. For

英語での記載にこだわる理由は何でしょうか？

a very literal translation might be

What is the reason that (you) insist on writing in English?

insist here is the closest thing I can think of in English that captures the nuance of choosing something in spite of implied norms or better practices.