hi
i have same,when i boot the first lauch does not start mining.i must kill the miner and start new one.
i was in 18.3.4,i updated to 18.6.1 to see...
So, @coke15 and @issie81, when you see a problematic gpu not starting to hash properly, do you see any error message from the initialization process? Or do you see a line with "Successfully initialized ..." for the gpu, but then it still doesn't start hashing ok?
All succesfull it starts mining for hours (sometimes longer) goes ok all of sudden 1 GPU drops others hashing at full speeds, after restart miner starts hashing back rinse and repeat..