Same Problem. The first note (an existing note I've had for years) I tried to edit has been reproducing itself. Created 20+ copies the first day. Multiple attempts at deleting them on ios Ipad failed. I could delete them but they would reproduce. Tried deleting on other devices - same issue.
Entire notebook is slow, unpredictable, and at time completely blank.
Hopefully they have an update coming out soon - its unusable for me in this version.