Unsure if you solved this in the end, but we had the same issue when upgrading from 2.4.2 to 2.4.3.
The issue for us was from some new logo arguments added to default.xml in 2.4.3:
<block class="Magento\Theme\Block\Html\Header\Logo" name="logo">
<argument name="logoPathResolver" xsi:type="object">Magento\Theme\ViewModel\Block\Html\Header\LogoPathResolver</argument>
<argument name="logo_size_resolver" xsi:type="object">Magento\Theme\ViewModel\Block\Html\Header\LogoSizeResolver</argument>
As we were overriding default.xml in our theme these were missing. Adding these arguments to our theme default.xml solved it.