ladspa-sinks not working reliable since wireplumber 0.4.9

PipeWire version: Compiled with libpipewire 0.3.48 Linked with libpipewire 0.3.48
Distribution and distribution version: Debian GNU/Linux 11 (bullseye)
Desktop Environment: GNOME 3.38.5
Kernel version: 5.10.0-13-amd64

Description of Problem:

For streaming to my home amp/raspberrypi I'm using a null-sink (connected with roc-send binary on its monitor) and airplay streaming with module-raop-sink/discover. Depending on the current wifi situation in our apartment building at times the one works better and at times the other. Each of these sinks is coupled with a ladspa-sink. Thus additionally I can choose more "compressed" audio output - e.g. for looking video late in the evening.

Since wireplumber 0.4.9 switching between these sinks is not working reliably any more: After switching around, the sound of the ladspa-sinks comes out of the onboard sound speaker.

Whereas the raop-/raop+ladspa-combination works fine as long there isn't any other ladspa-sink present (1.+2.), the null-/null+ladspa-combination failes as it is (3.).

How Reproducible:

1.) Load raop-discover and link a ladspa-sink to the raop-sink once it has been established. Start audio input (e.g. firefox audio stream). Toggle default sink around.

2.) Additionally load null-sink and link a ladspa-sink to it. Start audio input. Toggle default sink around.

3.) Load null-sink and link a ladspa-sink to it. Start audio input. Toggle default sink around.

Steps to Reproduce:

1.) pactl load-module module-raop-discover Wait 5 seconds until airplay sinks have been established... (sink_name = raop-sink-13 )

pactl load-module module-ladspa-sink sink_name=raop-sink-13+sc4 master=raop-sink-13 plugin=/usr/lib/ladspa/sc4_1882.so label=sc4 control=0.5,20,500,-30,5,1,5