No audible output to Sony WH-1000XM4 using LDAC codec

Summary

Using the latest Git tip build of PulseAudio at commit c6309a9c, with similar Git versions of GStreamer and gst-plugins-base and gst-plugins-bad, neither the A2DP nor HSP/HFP modes manage to produce any audio.

environment

pa-info.txt

Steps to reproduce

1. Build latest GStreamer and plugins with gst-build
2. Apply the PR 1793 to gst-plugins-bad and run build again
3. Enter the development environment of gst-build
4. Build PulseAudio from Git master with PR 473 applied.
5. Run PulseAudio daemon according to the Bluetooth patch info

What is the current bug behavior?

In A2DP mode, it appears to be using the ldac_hq mode, but produces no audible output. In HSP/HFP mode, the mono output appears to "test" forever, but also produces no output.

Additional information: ldac_mq and ldac_sq similarly produce no audio. aptx is unsupported. aac and sbc both produce working audio.

What is the expected correct behavior?

Both LDAC and HSP/HFP should have working audio.