Android 7.0 Nougat picks up default strings when device language is en_US

Question

As per the documentation in Language and Locale there have been improvements to Resource-Resolution Strategy from Android 7.0(API level 24) which is easy to understand with

Answer 1

I was having the same issue. After opening a bug report on Google Incorrect resource resolution strategy above Android N, defaulting to en_GB and not default strings.xml, they mentioned that this in the intended behaviour for Android N above. I'm quoting their reply here:

Starting in N, all English locales (except for US and US territories like Puerto Rico and American Samoa) fall back to some International English variant if such a locale is available.

So for en-CA, we would try these locales first, before falling back on en-GB (which is considered a representative of International English if there is no better International English locale): en-rCA (Canadian English), b+en+001 (International English), en (English). If you don't want en-GB strings to be picked up for en-CA, you should put resources in one of those three directories, as they would be considered a better match for en-CA.

So, it turns our en_UK is considered "a representative of International English". The strings will fall back to "International English" or its representative before en.