I'm so sorry for everyone having log-in issues. Must be super frustrating.
I hope S8 can figure out what the problem is.
Do you have a Chapter open? You can only collect Event items when any Chapter is open.
I have no issues with the Cows (do keep in mind drops are not guaranteed.. but the drop rate is pretty high, and they also drop multiples, so I don't think that's what you're experiencing)
Chapter 7 opens up today (in about 2 hours) :
Link to full Goal overview : https://forums.storm8.com/showthread...=1#post1664214
Everyone, make sure to check your inventory for Event items. Drops from the Castle are easily missed.
Good luck!