For a project with requirements that are too complex for Tiki calendars, I use the TrackerCalendar plugin. Currently the biggest problem is that not all items are displayed. It would be interesting to see if anyone has experienced this phenomenon before.
The items have several fields and belong to different categories. Depending on the user group or filter different items are missing. Inadequate access rights do not explain that an item is not displayed. If other items become invisible through a filter, the missing item reappears.
I have been fighting this topic for weeks. Of course the standard recipes are tried: Caches are emptied again and again and at least every night the search index is rebuilt. The problem occurs with Tiki 18.3 and 19.1. The problem occurs with MySQL Full-Text Search and Lucene. The problem occurs with MySQL 5.5 and 5.7.