sqlite - autoincrement field generates negative numbers

I have a strange issue with SQLite. If I run a query and add a record my autoinc field functions properly. Numbers go in sequence.

However, If I use the grid and the dbnavigator to add the record directly inside the grid , the autoinc field suddenly does not follow the sequence of numbers but adds -1 to the newly added record.

Is this a bug or some kind of normal behavior that I am unaware off ?