If you are getting 9MH/s it usually means that they are running at 300mhz engine core clock and not the operating engine core clock. With Claymore did you manually in the config file put in any overclocking values such as -vddc -cclock -mclock ? Maybe take those values out because they are causing issues.

If that is not your problem then try and plug in a monitor OR hdmi emulator cable to the GPUs which are running slower. Some operating systems and some GPUs only run at 300Mhz unless you got a monitor plugged into them. Usually you only need to plug it into the main PCIe 0 slot (x16 rail) and the rest should follow.