I am having the same problem on Quickbooks Self Employed. Select category, add note, add invoice, save and log out. Log back in and some notes have gone, its not me because I reopened entries and checked before logging out to make sure the notes were still there. I have just checked ones sorted this evening and every note entered today has gone. Happened several times. As a new purchaser of Quickbooks this really is not good enough, Save should mean save. trying to go back, researching the dam invoices all over again takes a lot of time especially as I am backloading some history. I have also noted that changing a category can wipe a note. To me as a new purchaser the programme is not living up to the hype and I am wondering if I made a mistake, and it cannot be anything to do with the version I have had the programme less than two months.