Could you tell us which distro + mesa? If I understand correctly, your state 1 mclk of 2500 MHz is stable on Linux, but pushing it to 2650 (as set on Windows) causes instability?
If so, could you tell us which Adrenalin version you’re using? The voltage floor for NV31 has sort of shifted since release; several users have found that their previously stable OC’s will no longer pass vulkan memory test (for example) on 23.20 and newer. Seems to be particularly noticable with AIB models as they can have substantially higher clocks than MBA ASICs.