XIAO RP2040 does 2M flash ID seems not to be unique

The flash used in this xiao module seems not have a unique id so for example pico_get_unique_board_id might return the same value for multiple boards. Seems like quite an oversight. Is this expected behavior for these boards? The GD25Q16 datasheet does mention the 4B request will return a unique id from the factory. Ive double checked pico_get_unique_board_id and this is issuing the 4B request to get the id