I have one rig with 4x RX580. The primary GPU (GPU0) is conected to monitor. If i disconnect the monitor, and watch with Teamviewer, Claymore (v11.0) dont pass to initilize the GPU's .He stop to sequence POLO/SOLO version and freeze. If i input the monitor cable , he go to the next step , find the GPU and make the dag for each one and finally work fine. I try to change the GPU0 and the same problem is present. Mean time the hrate for the GPU0 is less than the same GPU in not the GPU0.
Why dont you try some dummy plugs? Ive seen multiple posts particularly and users requiring this.