LMS + waveinput plugin + Sqeezelite on a RaspberryPi

Here is my setup :
A first rasbperryPi in my living room. It acts as the server (running LMS) and as a player (with Squeezelite). It uses a Wolfson audio card.
A second raspberryPi in the kitchen, running only Squeezelite.

On both raspberryPi, Squeezelite is launched with this command:
And the URL for waveinput is This setup is working fine when listening to web stream or local audio files.

Then, I tried the plugin Waveinput. My goal is to be able to stream an analog source on the 2 players. So, I connected my audio source to the lineIn input of the wolsfon audio card and made sure that it was working fine :
This command acquires the audio from the LineIn and outputs it on the SPDIF output of the audio card. Perfect!

But waveinput didn't work : the stream seems to start for 5sec and then stops. I found out that it is working only if Squeezelite is not running on the 'server' (the raspberrypi that runs LMS). If squeezelite is not running on the server, LMS is able to record the audio from the input and transmit it to the player in my kitchen.

Is there any conflict between LMS/Waveinput and Squeezelite because they are both trying to access to the audio card?

Any ideas?

Thanks!