Pyjnius: Exception calling PythonActivity.getWindow().setSoftInputMode(...)

I get a pyjnius error with a lot of class method accesses I expect to work:

Traceback (most recent call last):
  File "jnius/jnius_export_class_pxi", line 752, in jnius.jnius.JavaMethod.__call__
  File "jnius/jnius_export_class.pxi", line 699, in jnius.jnius.JavaMethod.ensure_method
jnius.jnius.JavaException: Unable to find a None method!

Steps to reproduce:

1. Make a new folder with this main.py:

from jnius import autoclass
python_activity = autoclass('org.kivy.android.PythonActivity')
window = python_activity.getWindow()
window.setSoftInputMode(16)  # SOFT_INPUT_ADJUST_RESIZE

1. Package as .apk:
   p4a apk --arch=armeabi-v7a --name test --package com.example.test --version 1 --requirements=kivy,python2 --private . (or python 3, you may need to add api and/or ndk api arguments if these aren't set in your path)

2. Run and wait until it instant-terminates, and then check logcat. You'll see this:

Traceback (most recent call last):
  File "jnius/jnius_export_class_pxi", line 752, in jnius.jnius.JavaMethod.__call__
  File "jnius/jnius_export_class.pxi", line 699, in jnius.jnius.JavaMethod.ensure_method
jnius.jnius.JavaException: Unable to find a None method!