Notebook keeps losing my data

I had this problem a lot in the past and compensated for it by always copying the entire text of a note before closing it, but it seemed to be fixed and after many months of good behaviour from the app, I stopped doing that.

Too bad for me, as today, I spent all morning compiling info to plan and launch my new Instagram account and when I closed the note and came back to it, everything I'd added today was gone.

I hope someone can tell me what might be going on, because I can't continue to use this platform if I can't trust that my data could be lost at any time.