Description of the issue

Since v2.21.1 (v2.22.1 included) some statements like ReturnStmt don't return any Expr with getExpr(), nor any Element with getAChild(). This works as expected in v2.21.0.
Also, the (expected) child Element doesn't have a getParent() neither.

You can try it with this example:

public static class A {
    static int get() {
        return 10;
    }
    static  void Main() {
    }
}

And these CodeQL queries:

from ReturnStmt r
select r, "number of children: " + r.getNumberOfChildren()

Got:

|      r      |         col1          |
+-------------+-----------------------+
| return ...; | number of children: 0 |

Expected 1 or more children

from ReturnStmt r
select r, "Expr: " + r.getExpr()

and

from ReturnStmt r
select r, "Expr: " + r.getAChild()

With both I got empty result. Expected the 10 of the return 10; statement.