linux - du -sh : I don't get why these two results are different

I need to know the size of a folder and some of its sub folders. So I'm trying to use the du command.

I cd into the right directory and then try (in bash) :

[xxx@yyy TEST]$ du -sh .
4.1G    .

[xxx@yyy TEST]$ du -sh *AAA
3.2G    123_AAA

[xxx@yyy TEST]$ du -sh . *A
4.1G    .
2.7G    123_AAA

How is it possible that I get different results for the size of 123_AAA (3,2GB then 2,7GB) with my second and my third command ?

Thank you in advance

Answer

I think du is aware of hardlinks. Try du -shl . *A .