rig 1
r9 280x oc 1120/1500 - 245 h/s
r9 390  oc 1150/1500 - 365 h/s
rx 480  oc 1250/2150 - 265 h/s (bios mod)

this rig gets none shares rejected

rig 2
6x r9 390 oc 1130/1500 - 340-360 h/s total = 2140 h/s

this rig is getting a lot of shares rejected since v10

any hint for rejected shares? rigs are in different places and ISPs.