Direct Mail Seed Addresses

I have a custom table from which I want to send DM and include seed addresses. I have extended the seedMember table to add new table and some of it's fields. 

However when I create a seed, add the required fields and then add the seed to the send for a DM  it does no substitution at all. The only error I can see in the log is 

"DLV-490122 The contact of the 'SDM1879' seed address is not specified. Please provide this information."

Any ideas?

I am using the same table and seeds for email and that works fine.

The nms:seedMember extension is shown below The custom table is actually a Snowflake view accessed by FDA in Adobe 7 Classic

<srcSchema _cs="Seed addresses (three)" created="2022-11-01 21:28:58.936Z" createdBy-id="0"
desc="Seed to insert in the export files" entitySchema="xtk:srcSchema"
extendedSchema="nms:seedMember" img="nms:unknownad.png" label="Seed addresses"
labelSingular="Seed" lastModified="2022-11-02 08:20:47.414Z" mappingType="sql"
md5="DE679B0ED73FAB5612EEBAF0AAA09355" modifiedBy-id="0" name="seedMember"
namespace="xxx" xtkschema="xtk:srcSchema">

<element desc="Seed to insert in the export files" img="nms:unknownad.png" label="Seed addresses"
labelSingular="Seed" name="seedMember">

<element label="Contact Rules" name="custom_snow_CONTACT_RULES">

<attribute name="FIRST_NAME" template="snow:CONTACT_RULES:CONTACT_RULES/@FIRST_NAME"/>
<attribute name="EMAIL" template="snow:CONTACT_RULES:CONTACT_RULES/@EMAIL"/>
<attribute name="SMS" template="snow:CONTACT_RULES:CONTACT_RULES/@SMS"/>
<attribute name="TITLE" template="snow:CONTACT_RULES:CONTACT_RULES/@TITLE"/>
<attribute name="LAST_NAME" template="snow:CONTACT_RULES:CONTACT_RULES/@LAST_NAME"/>
<attribute name="CONTACT_ADDRESS_LINE_1" template="snow:CONTACT_RULES:CONTACT_RULES/@CONTACT_ADDRESS_LINE_1"/>
<attribute name="CONTACT_ADDRESS_LINE_2" template="snow:CONTACT_RULES:CONTACT_RULES/@CONTACT_ADDRESS_LINE_2"/>
<attribute name="CONTACT_ADDRESS_LINE_3" template="snow:CONTACT_RULES:CONTACT_RULES/@CONTACT_ADDRESS_LINE_3"/>
<attribute name="CONTACT_CITY_NAME" template="snow:CONTACT_RULES:CONTACT_RULES/@CONTACT_CITY_NAME"/>
<attribute name="CONTACT_ZIP_CODE" template="snow:CONTACT_RULES:CONTACT_RULES/@CONTACT_ZIP_CODE"/>

</element>
</element>

</srcSchema>