Binding library runtime error: java.lang.NoClassDefFoundError for java.util.function.Supplier

Hello, just been using Xamarin for about a week and I'm trying to create bindings for a library supplied by a third party vendor (.aar format). I've created a new bindings library and followed the instructions supplied in the documentation. When using the resulting bindings, I'm getting a runtime error that mentions java.util.function.Supplier, which I assume is part of the base library. I've spend a few days trying to track down what may be going wrong, but I fear that I'm looking in the wrong places or that I am missing some vital bit of insight. The error is as follows and happens upon calling into the bound library after clicking a button (not sure if there is more that may be relevant, as I'm pretty new to this):

10-10 16:53:55.511 I/sentials.mobil(10488): Rejecting re-init on previously-failed class java.lang.Class<com.vendorName.VendorName$a>: java.lang.NoClassDefFoundError: Failed resolution of: Ljava8/util/function/Supplier;
10-10 16:53:55.511 I/sentials.mobil(10488):   at java.lang.Class java.lang.Class.classForName(java.lang.String, boolean, java.lang.ClassLoader) (Class.java:-2)
10-10 16:53:55.511 I/sentials.mobil(10488):   at java.lang.Class java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader) (Class.java:453)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void md5f92e0daf340890c9667469657ee2ece8.ButtonRenderer.n_onClick(android.view.View) (ButtonRenderer.java:-2)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void md5f92e0daf340890c9667469657ee2ece8.ButtonRenderer.onClick(android.view.View) (ButtonRenderer.java:95)
10-10 16:53:55.511 I/sentials.mobil(10488):   at boolean android.view.View.performClick() (View.java:6597)
10-10 16:53:55.511 I/sentials.mobil(10488):   at boolean android.view.View.performClickInternal() (View.java:6574)
10-10 16:53:55.511 I/sentials.mobil(10488):   at boolean android.view.View.access$3100(android.view.View) (View.java:778)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void android.view.View$PerformClick.run() (View.java:25885)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void android.os.Handler.handleCallback(android.os.Message) (Handler.java:873)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:99)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void android.os.Looper.loop() (Looper.java:193)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6669)
10-10 16:53:55.511 I/sentials.mobil(10488):   at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run() (RuntimeInit.java:493)
10-10 16:53:55.511 I/sentials.mobil(10488):   at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:858)

Note that com.vendorName.VendorName$a seems to be a private inner class of com.vendorName.VendorName.

Any help or pointers are greatly appreciated!