As
@BP_6 alluded to, most of these studies haven't been debunked per se, because they're not wrong, but have been explained to lead quite clearly to other conclusions than what the studies suggest.
When the body is sick or dying, for example in cancer/drug addiction/etc, it is extraordinarily common for LDL to absolutely collapse. Total cholesterol (to your 220 point) also often collapses, because as we know HDL also drops in the presence of sickness and insulin resistance.
If you look at hospital mortality as BP_6 notes, the highest mortality are in those individuals with low to low-normal blood pressure rather than high blood pressure, because it shows they are dying. It doesn't mean that high blood pressure is good for health!
Beyond the mountains of literature showing clearly that lipid lowering
and health-span with seemingly no lower limit, the final nail in the coffin for the too-low-might-be-bad argument is studies relating to those with a nonfunctional PCSK9 gene, the same gene PCSK9 inhibitors like Repatha work on. These individuals have hilariously low cholesterol, with LDL's oftentimes well below 30, and yet have seemingly ZERO negative impacts from the lack of LDL. They just don't get heart disease!