I run QWP on 2 PC's, my 'primary' and a backup. I don't go into it too often on the backup, but I did just now, and found several fake/duplicate [Edited-Readability] accounts yet again. Pretty much every single account. With Chase and Discover Card, it takes real accounts and makes fake versions of them with piles of transactions from the real ones. It's a royal [Removed-Language] to clean out. This time it took about 2 hours, deleting 'new' transactions that went into them instead of the real accounts, closing them out, then resetting things (which got some, not all transactions into the right place), then looking for what accounts were still wrong, and manually downloading them. This seems most likely to happen when there are software updates, also download type updates.
I also found that Amex, though its connection appears to be the current type, hadn't downloaded transactions in many weeks. But no duplication there.
I did software development for financial institutions for many years, also was a DBA, project leader, systems manager, analyst… If I'd ever have software this sloppy, I'd have been unable to work. [Removed-Speculation]
I do wonder, though, how many of these problems are caused by miscommunication between Quicken servers and Intuit servers, though I've no way to know.