Hi again Jessica
Many of us here use past store bought milk, but they are not all created equal, some are past at different temperatures to others and some have more antibiotics to others that are harder to coagulate. Some info on poor coagulation
Sounds like you still aren't getting a good curd set, what type of rennet, where did you get it, how much, did you dilute before adding? What temp is the milk at?, how did you mix it in? I'd increase your rennet dosage as it sounds like you are still getting poor curd formation.
Here's another Asadero recipe
that uses a Thermophilic (high temp) starter culture. I don't know of anyone making Asadero on this forum, plus moz type cheeses are very tough to master.
OK, that's not much help, hope others can advise here as I have no experience making this or moz type cheeses.