Dropbox Sync Android arm64 support

Hello there,
I'm using the Dropbox Sync API (mostly for the use of the Datastore, but also some file access). In my Android app I'm current the following crash report from a Nexus 9 Android tablet:

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file "/data/app/net.geero.prayermate-1/base.apk"],nativeLibraryDirectories=[/data/app/net.geero.prayermate-1/lib/arm64, /vendor/lib64, /system/lib64]]] couldn't find "libDropboxSync.so"
at java.lang.Runtime.loadLibrary(Runtime.java:366)
at java.lang.System.loadLibrary(System.java:989)
at com.dropbox.sync.android.NativeLib.ensureLoaded(NativeLib.java:70)
at com.dropbox.sync.android.NativeLib.<clinit>(NativeLib.java:32)
at com.dropbox.sync.android.CoreAccountManager.initNativeLib(CoreAccountManager.java:228)
at com.dropbox.sync.android.CoreAccountManager.<init>(CoreAccountManager.java:141)
at com.dropbox.sync.android.DbxAccountManager.getInstance(DbxAccountManager.java:200)
at com.dropbox.sync.android.DbxAccountManager.getInstance(DbxAccountManager.java:160)
at com.dropbox.sync.android.DbxAccountManager.getInstance(DbxAccountManager.java:107)
...

I can't see any libDropbox.so in an arm64 folder - any idea what's going on?
(is it possibly because I another another NDK dependency that has an arm64-v8a .so file? If so, can I make a copy of one of the existing dropbox so files into an arm64-v8a folder? if so, which one is best?)