Since this discount is attached to a coupon, its Status and date fields are controlled by the coupon rather than the discount — Microsoft's docs are explicit that those fields become unavailable once Coupon code required is set to Yes. My guess is that the validation which normally runs when you enable a discount directly doesn't fire on the coupon path, which would leave validation status at "Not run."
Worth testing: does a free item discount that isn't linked to a coupon show a validation status after you enable it? If it does, that points at the coupon path rather than your setup.
More to the point — is the discount actually applying on orders? If it is, "Not run" may just be cosmetic. If it isn't, that's the real question and worth asking directly.
