Hi @journeyman_73
From what I can see in your template, the variable
$block
is equal to
Magento\Cms\Block\Block
so
$block->getBlockCss()
$block->getBlockTitle()
need to be methods / functions defined in:
Magento\Cms\Block\Block.php
Regarding the CMS block you are trying to render with:
<?= $block->getChildHtml() ?>
Try creating another block child of the one you already have. Something like this:
<block name="store.footer.col.3" template="Magento_Theme::html/footer_links_block.phtml" after="store.footer.col.2">
<block class="Magento\Cms\Block\Block" name="store.footer.col.3">
<arguments>
<argument name="block_id" xsi:type="string">footer_links_block</argument>
</arguments>
</block>
</block>
Hope it helps