API get /instances?recursion=2 not showing snapshots size

LXD
1

LXD 4.2

API get /instances?recursion=2

                                [last_used_at] => 0001-01-01T00:00:00Z
                                [name] => snap20
                                [profiles] => Array
                                    (
                                        [0] => pl3
                                    )

                                [stateful] => 
                                [size] => -1

but recursive snapshots call, shows the snap size correctly:
API get /instances/snapshots?recursion=2

                [last_used_at] => 0001-01-01T00:00:00Z
                [name] => snap20
                [profiles] => Array
                    (
                        [0] => pl3
                    )

                [stateful] => 
                [size] => 71168
            )
2

This is intentional as getting snapshot size can be extremely expensive (up to several minutes per snapshot on Ceph or dir backend).