setup:db-declaration:generate-whitelist does nothing – no results or errors

M2.4.3-p1. Trying to use db_schema.xml as that appears to be the way forward. setup:upgrade is not adding my tables. setup:db-declaration:generate-whitelist is not generating the whitelist. Basically nothing is happening and no errors are being shown/logged. I understand previous versions of Magento would silently fail but apparently this was addressed in 2.4.x. Now supposed to give us something useful (as should all commands!). I added some further logging as per this: Magento 2 is not generating the db_schema_whitelist.json file via CLI, but still nothing being logged.

Can anyone spot what is wrong with this:

<?xml version="1.0"?>
<schema xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:Setup/Declaration/Schema/etc/schema.xsd">

    <table name="alp_tablepricing_quantities" resource="default" engine="innodb" comment="TablePricing Quantities">
        <column xsi:type="int" name="quantity_id" unsigned="true" nullable="false" identity="true" comment="Quantity Id"/>
        <column xsi:type="int" name="product_id" unsigned="true" nullable="false" comment="Product Id"/>
        <column xsi:type="int" name="quantity" unsigned="true" nullable="false" comment="Quantity"/>
        <constraint xsi:type="primary" referenceId="PRIMARY">
            <column name="quantity_id"/>
        </constraint>
    </table>

    <table name="alp_tablepricing_prices" resource="default" engine="innodb" comment="TablePricing Prices">
        <column xsi:type="int" name="price_id" unsigned="true" nullable="false" identity="true" comment="Price Id"/>
        <column xsi:type="int" name="product_id" unsigned="true" nullable="false" comment="Product Id"/>
        <column xsi:type="int" name="quantity_id" unsigned="true" nullable="false" comment="Quantity Id"/>
        <column xsi:type="int" name="option_one_id" unsigned="true" nullable="false" comment="Option One Id"/>
        <column xsi:type="int" name="option_two_id" unsigned="true" nullable="false" comment="Option Two Id"/>
        <constraint xsi:type="primary" referenceId="PRIMARY">
            <column name="price_id"/>
        </constraint>
    </table>

    <table name="alp_tablepricing_customprices" resource="default" engine="innodb" comment="TablePricing Custom Prices">
        <column xsi:type="int" name="customprices_id" unsigned="true" nullable="false" identity="true" comment="Custom Price Id"/>
        <column xsi:type="int" name="product_id" unsigned="true" nullable="false" comment="Product Id"/>
        <column xsi:type="int" name="custom_attribute_option_id" unsigned="true" nullable="false" comment="Attribute Id"/>
        <column xsi:type="int" name="option_one_id" unsigned="true" nullable="false" comment="Option One Id"/>
        <column xsi:type="int" name="option_two_id" unsigned="true" nullable="false" comment="Option Two Id"/>
        <column xsi:type="decimal" name="price" scale="6" precision="20" unsigned="false" nullable="false" default="0" comment="Price"/>
        <constraint xsi:type="primary" referenceId="PRIMARY">
            <column name="customprices_id"/>
        </constraint>
    </table>
    
</schema>