Occurrence table does now have langcode column. This creates issue for multilingual website, if the recurring field is translatable. For a given entity update, Occurrence table "date_recur_*" is searched for entity id and deletes old entry before saving new. This results in deletion of all the language translations entity values.
date_recur__node__field_activity_dates table. you will see activities of English translation, but Dutch activities are not presentAdd langcode column to "Occurrences tables" schema and use it to delete any entries why editing or delete any content
Active
3.1
Field Storage
This patch added langcode to Occurence table schema, and uses it while adding or deleting entries
This certainly needs appropriate test coverage.