I believe we've finally tracked down the root cause of this issue, and a set of patches has come across that should resolve it.
I haven't yet tried these latest patches but instead an earlier trial based upon v6.4-rc4, which worked well. Two patch sets resolve the issue; I haven't tried just the latest, but I believe both are required for correct operation: - https://lore.kernel.org/linux-acpi/20230601221151.670-1-mario.limoncie...@amd.com/T/#u - https://lore.kernel.org/linux-gpio/20230630194716.6497-1-mario.limoncie...@amd.com/T/#u