5x470 v9.3 1066H/s >>v10.0 1130H/s. 20 hour stable work. rejected shares 0.11%

on my "test rig" with one 280x (-a 2 -i 7) 220H/s but after 30-40 min hashrate up to 260H/s and many many rejects. pool is nanopool. 8 hour of work approx 25% of rejected shares. revert to 9.2