With 21 Mhs +++ after Compute mode, seem like your card running at stock bios. For make sure, use AB and set it to a default setting then take the pic, post here.

Error 43, most caused by a driver issue. Yes, you can try to patch the driver (even when you are running on stock bios). Or, load different driver (I suggesting blockchain version) for manually updating your 580 (4GB).