Adding a pulsesrc bin in my pipeline freeze the pipeline

[Jack]

Hello,

I have a pipeline in which i mix two bin sources containing a
uridecodebin through an adder. At this point the pipeline is in playing
state and i can listen the sound.

But, adding a new source bin containing a pulsesrc to the adder, the
pipeline freeze.
Then, removing this bin makes the pipeline works again.

I don't know what I have to do to get a working pipeline with this 3 bin
sources ?
Any clue ?
Best!
++

Jack