When there is a CHECK constraint on a virtual column that allows NULL and the column is not specified in an INSERT, then the constraint is not checked:

CREATE TABLE tv2(c1 int, c2 int AS (c1 + 1) VIRTUAL, CHECK (c2 is null or c2 > 2));

The following fails, which is correct:

INSERT INTO tv2 VALUES(1,1);

The following succeeds, which is also correct:

INSERT INTO tv2 VALUES(2,1);

The following though is also successful, which is incorrect (c2 will have the value 2):

INSERT INTO tv2(c1) VALUES(1);