I try to understand why there is an error in the following case stating that a table was "not locked" even though a (WRITE) LOCK was issued just before.

This is the setup (MySQL / MariaDB):

CREATE TABLE A
(
    id INT
);

CREATE TABLE B
(
    id INT
);

Here are the cases (first one being the failing one):

# does not work --> Error: "Table 'B' was not locked with LOCK TABLES" on 2nd statement
LOCK TABLES A WRITE, B WRITE;
INSERT INTO A (id) VALUES ((SELECT 1 FROM B)), ((SELECT 2 FROM B));
UNLOCK TABLES;

# works (single statements)
LOCK TABLES A WRITE, B WRITE;
INSERT INTO A (id) VALUES ((SELECT 1 FROM B));
INSERT INTO A (id) VALUES ((SELECT 2 FROM B));
UNLOCK TABLES;

# works (table aliases)
LOCK TABLES A WRITE, B tb1 WRITE, B tb2 WRITE;
INSERT INTO A (id) VALUES ((SELECT 1 FROM B tb1)), ((SELECT 2 FROM B tb2));
UNLOCK TABLES;

What causes the error in the first case?

Edit: I simplified the example again to the bare minimum.