I've noticed that not all my customers who download a product get tagged automatically for that product. When I went into the product there doesn't appear anywhere for me to add in a tag, however I clearly remember there being a tag to choose in the past. I could choose a tag in an email section but not in a product section.
Some customers are automatically coming up with the tag attached, while others that are downloading the product aren't.
So how do I know they are actually receiving the nurture email sequence if there is no tag beside their name?