wasapisink: Does not work correctly in live pipelines

Hello

As the subject says... I have a pipeline which works on Linux:

audiomixer name=mix ! audioconvert ! audioresample ! autoaudiosink 
interaudiosrc ! audioconvert ! mix.  
audiotestsrc ! audioconvert ! interaudiosink

However, on Windows there's no sound. The GST-DEBUG=3 output with autoaudiosink is

FIXME  default gstutils.c:3981:gst_pad_create_stream_id_internal:<audiotestsrc0:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
0:00:00.130119900 16312   034256B8 FIXME default gstutils.c:3981:gst_pad_create_stream_id_internal:<interaudiosrc0:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
0:00:00.157495900 16312   03425820 FIXME basesink gstbasesink.c:3145:gst_base_sink_default_event:<autoaudiosink0-actual-sink-wasapi> stream-start event without group-id. Consider implementing group-id handling in the upstream elements
0:00:00.465267200 16312   03425820 WARN audiobasesink gstaudiobasesink.c:1491:gst_audio_base_sink_skew_slaving:<autoaudiosink0-actual-sink-wasapi> correct clock skew -0:00:00.130468800 < -+0:00:00.020000000

It works when I replace autoaudiosink with directsoundsink, while I get the same messages when I put wasapisink.

Thanks, Tom