Already tried several.
Even tried running only 4 cards and then switching paces on motherboard and switching resizes.
In every situation always one card (usually GPU 2) will get hanged in OpenCL call and miner will get stuck.
So basically form hardware point of view checked every possible scenario to triple check every component.
I'm not sure if software troubleshoot will help...

Use DDU uninstaller and then install drivers again on clean system.