Fail to input Chinese in CEP <input> label sometime

We are currently experiencing a persistent issue during the development of our CEP plugin. Specifically, we're having trouble with the <input> tag in our plugin. While English characters and numerals can be input without problems, we often find that we're unable to type Chinese characters into the input field, despite trying several different input methods.

Interestingly, on rare occasions, we are able to type Chinese characters into the input field. However, once we click outside the CEP plugin, we lose this ability.

We are hoping someone might be able to offer a resolution to this issue. We appreciate your assistance and thank you in advance for your time.