One correction - MM's don't short in the traditional 'short' parlance. But since they set up the buys and sells, and since those are not finalized for 2 days, they are 'short' for that period. That's what the short list on OTC Markets shows.
It's too bad they named it 'short' because shorting a stock intentionally means you have to buy it back at some point. MM's don't do that, they simply buy from a seller and sell to a buyer, and those shares are short until settled.