When you restart the rig wait for 12-15 minutes before you start Claymore. That freeze also happend to one of my rigs after restart and the only solution for me is to wait before I start miner. It`s unbelivable but that help.
Delay should be only 1 minute at most, there is no need for more than that.
Yes I know but my rig freeze`s than. i dont know what happend with driver or something else in that period of 12-15 minutes but that is the only thing that helps for normal start of claymore.