After creating a second card for each DEFINITION type note, I modified my database with the following SQL queries:
DELETE FROM cards WHERE ord=1;
UPDATE cards
SET ord=1 WHERE nid=(SELECT id FROM notes WHERE nid=id AND mid=1519833316765);
UPDATE cards
SET nid=(SELECT id FROM notes WHERE mid=1519833316765 AND sfld IN (SELECT sfld FROM notes WHERE id=nid));
DELETE FROM notes WHERE mid=1519833278399;
And I am studying the database in duplicate, on one side (on the left) the old unmodified database and on the other (on the right) the modified database. As you can see, all the reviews are identical (since I modified the database on 19 May) except the one for today, 20 May. The only data that differs is the response time and, the reason for my bewilderment, the interval.
I am using Anki desktop 2.1.43 to study both decks with the new scheduler 2.1.
How can it be that with the same factor the interval is different?