Hello, I have 3 x MSI rx6600s (non-xt) cards which are behaving strangely when I use the -cvddc command. Running under windows 10.

One of the cards will happily change voltage via phoenixminer using e.g. -cvddc 750 or -cvddc 800 or whatever. Works fine using 750, pulls about 55w which is ok.

The other 2 cards automatically crash the driver (and the card won't generate a DAG) whenever I try to set core voltage via commandline for some reason - regardless of what voltage I set. Even if it's -cvddc 800 or 900 or 1000 or 1100 or whatever (more than it should need), the 2 cards won't change voltage via phoenixminer.

Both these cards WORK FINE when you don't set voltage via phoenixminer, and you can change their voltage via the radeon software no problems.
The cards behave the same regardless of which PCI slot they're in, or whether or not they use a riser.
Same behaviour in phoenixminer 5.8b or 5.8c.
Same behaviour using either AMD drivers that support 6600 non-xt cards (21.10.2 or 21.10.3)

Does anyone have any suggestions for this issue? (other than "install linux"). Is this an issue with the driver, miner, or cards? (although if this was happening on one card I would think perhaps it's the card, but 2 out of 3 seems unlikely).

Thanks in advance for any assistance.