I now have several Radeon VII doing 98Mhs in Windows, I'm just using the strap 2 option in the driver. Distance between the cards is important as well as fan speed.
Could you share your settings: core, mem vltg and power usage? I'm not seeing anything about a strap option in the info files in the miner...I see a "C" option for VII on linux
My clocks with no strap are core 1550 mem 1100 vltg 850 at about 84.7 @ 144 watts on eth Windows