This issue is caused by the invariant culture. Since the Singapore site has only 1 language, the culture is invariant and not treated as En, when the content moves to China site where there are 2 languages, the default language is Chinese and is considered as invariant and as such the invariant from Singapore site is matched to Chinese.
To work around this, please, add another language(just add it it does not need to be used) this will cause the English to be matched as expected in the China site.
Please note that the already existing items prior to the addition of the second language need to republished in order for the changes to take effect.
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