hardware dont work together

Hi, 
I have 1x DJM V10, 1x DDJ-RX and 1x CDJ3000. 
all devices are connected via USB hub and the DJM and V10 are connected with LAN as well. Connected is a Mac M3 chip. I open recordbox via my mac. all times when I start a track the I see a red level on the RX. On my V10 I can here the sound but the red level on the RX let me scared. 
What is wrong with my set up. 

I put this devices together because I wait for my 2. CDJ3000 but the deliver time is still long. 

I use the hardware unlock plan. 
Is there how can help me?