Not sure if this is your problem but you have universe 25 starting channel 1 with 600 channels on output 4 and on output 16 you have universe 25 starting channel 211 which i think should be universe 26 start channel 91
Andy
From memory and its been a while since i have set up my dmx lights i think each light needs 3 channels so your first needs to start on 50 and your second on 53 and third on 56 etc
Looks like your channel config in xlights is wrong. You have 320 pixels in pixlite config for universe 1 which is 660 channels and only 336 channels in xlights config
I use these and run them off my pixlite 16
http://www.aliexpress.com/item/DC12V-input-10W-RGB-DMX-LED-flood-light-IP66-with-13-5mm-4core-waterproof-pigtails-input/32249441206.html
I have 4 daisychained and run off one DMX output
It happens when power is on, not while running a sequence. External antenna in line with my controller box. Is there any quick fix rather than changing power supplies?