Currently using 3.02 mac version, on Yosemite. I think this problem appeared several minor versions ago, not sure.
Basically, I edit an older entry, such as adding a new field with label. If I click away from this entry, say, on another entry, and then click to go back, the data is gone. Only the new label line with blank field remains. Sometimes it does this and sometimes it works fine.
Adding to this problem is syncing. Even if the new data finally seems to have saved itself on the desktop, syncing with my android phone (using restore mode on phone, obviously), I get the entry on the phone with the label, but AGAIN the field is blank on BOTH platforms.
I have been forced to redo every step many times to get this thing to save and it is scary. I believe it might also happen with new entries, but it’s hard to say at this point.