Integrate Filter Bar with WPML
Here it says that Filter Bar is not integrated with WPML and that there are no plans: https://theeventscalendar.com/knowledgebase/wpml-support/
I vote for integrating this with a high priority.
There is one forum post from Barry, which gives an idea: https://theeventscalendar.com/support/forums/topic/hook-into-filter-bars-event-category-to-achieve-wpml-translation/
Thanks to a recent Pull request and the “Translate texts in admin screens »” (as explained here for date and time translation: https://theeventscalendar.com/knowledgebase/setting-up-the-events-calendar-with-wpml/), Filter Bar now works like a charm with the Events Calendar and the Events Calendar Pro