Activated a few days ago. It perhaps causes an issue: https://dev.tiki.org/item7138-Indexing-failed-while-processing-XXX-type-YYY-with-the-error-normalizer-sortable-not-found-for-field-sort
Permalink: https://tiki.org/blogpost788-Unified-Index-fall-back-if-Elasticsearch-is-unaccessible