I kept playing Act 2, and I got the 5th bag in the Act 2 quest Clear the Way. So there we go. Both my characters that had the fifth bag in the past had also made it past that point. Mystery solved!
I am agonizing over all these purple equipment choices. Which one I choose changes my character so much. One set of purple pants would be much more defensive compared to my offensive pants right now. One belt I could wear would increase my defensive ability by a lot, but change my resistances by a lot, so I’d have to change other equipment around to compensate.
I’m just going to take the lazy way as usual and just keep plowing through with what I’m wearing until I start having trouble.