Sixth annoyance: Imported transactions are often not matched correctly with entered transactions when the date varies by more than a day or two.
Jess will often buy something online and dutifully enter the transaction that day. But often a vendor won't actually charge her card until the item ships, meaning that the date on the imported transaction will be a few days later than the one she entered. YNAB will often fail to match the two, leaving the entered transaction as uncleared and creating a cleared-but-erroneous copy of it.
These are often easy to spot but it's a needless annoyance. Perhaps the problem is being exacerbated by my fourth annoyance above (poor vendor name matching).