Zend certified PHP/Magento developer

complex type ‘mixedDataType’: The content model is not determinist

I have an issue on a Magento 2.4.4-p1 instance that appeared during the night somehow.

The indexation process for inventory is not working anymore, as well as the category page which is not loading due to the following exception:

1 exception(s):
Exception #0 (MagentoFrameworkConfigDomValidationSchemaException): Processed schema file: /home/m2upgrade/public_html/vendor/magento/module-elasticsearch/etc/esconfig.xsd
complex type 'mixedDataType': The content model is not determinist.
Line: 18

I tried to find some non-determinist records, and duplicated values, but nothing so far.

Did someone encounter this error in the past?