DOKTOR read this pls. Why i must start xmr-stak for enable HBM? enable-disabe card in device manager not work.
As i don't have vega gpu's i can't really help you, but if you use
"restart_devices_on_startup" with the new
"restart_devices_on_startup_script", it should give back full speed to your Vegas, and in the script you can add undervolting overclocking etc with overdriventool.
Or try what
@lebuawu2 wrote.
But the disable/enable should be enough tho.
Download V1.5.1 and try it.
disable and enable only work for blockchain driver for CN / CN-V7 maybe for CN-Heavy also. for new driver 18.3.4 no need to disable and enable again in order to get best hashrate for CN / CN-V7 but for CN-Heavy apparently didn't work.