Is DocumentFile API broken on encrypted removable SD card on Samsung Galaxy S7?

I have created a zero size file aaa.txt on the root folder of the UNENCRYPTED removable SD card. The file aaa.txt has correct size 0 bytes when I list all entries in the root folder with DocumentFile#listFiles().

If I encrypt removable SD card from “Settings” -> “Lock screen and security option” -> “Encrypt SD card” and call DocumentFile#listFiles() again,
I get size 8192 bytes!

As I suppose DocumentFile API should show me the same size for both encrypted and unencrypted cases. Device model Samsung Galaxy S7 with Android 7.0.