ProtocolError on receive_data after connection is closed

I am randomly getting this error on h2 3.1.1 (about once a week on a busy H2 client):

Traceback (most recent call last):
  File "site-packages/h2/connection.py", line 224, in process_input
    func, target_state = self._transitions[(self.state, input_)]
KeyError: (<ConnectionState.CLOSED: 3>, <ConnectionInputs.RECV_PING: 14>)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "nameclient.py", line 84, in recv_task
    for event in self.conn.receive_data(data):
  File "site-packages/h2/connection.py", line 1463, in receive_data
    events.extend(self._receive_frame(frame))
  File "site-packages/h2/connection.py", line 1486, in _receive_frame
    frames, events = self._frame_dispatch_table[frame.__class__](frame)
  File "site-packages/h2/connection.py", line 1725, in _receive_ping_frame
    ConnectionInputs.RECV_PING
  File "site-packages/h2/connection.py", line 229, in process_input
    "Invalid input %s in state %s" % (input_, old_state)
h2.exceptions.ProtocolError: Invalid input ConnectionInputs.RECV_PING in state ConnectionState.CLOSED

Unfortunately the code is somewhat complicated but I believe the connection closing logic to be correct. I never call close_connection and I quit receiving once ConnectionTerminated appears.

Possibly H2 is internally closing the connection due to ping timeout or other issue, and then throws me an error when the peer still sends something. Quite likely this actually happens when my laptop is in sleep, and H2 going ping-timeout meanwhile, with some data still in receive buffers. I would expect a ConnectionTerminated event in that case, after any remaining events are relayed, not an exception.

Beginne in h2/connection.py bei receive_data, _receive_frame, _receive_ping_frame und process_input rund um die gemeldeten Zeilen. Reproduziere oder modelliere einen Ping, der eintrifft, nachdem die Verbindung CLOSED erreicht hat, und prüfe die vorhandenen Tests für Verbindungsbeendigung und gepufferte Frames. Als erledigt gilt, dass verbleibende empfangene Frames ohne diesen ProtocolError verarbeitet werden und die Beendigung wie beschrieben als Ereignis gemeldet wird.