Hi, I have an error with ACF Pro and the The Events Calendar Relationship fields. I am I have tested this on my custom theme and with a brand new clean install with just WordPress, the Twenty Twenty-One Theme, ACF Pro (Version 5.9.9) and The Events Calendar (Version 5.8.1) – all updated.
My issue is that when I create a Field Group and create a field with a type of Relationship and set the (Filter by Post Type) to “Event” (The CPT for The Event Calendar) I go to the post and add the events I have created in the relationship box and save the post all looks to be okay but when I leave the post and then go back to that same post NO events are in the selected area. Yes the output is correct as if i add a event save its shows that event on the front end and if I then go in and add a different event it will show that one.
Again only the theme, acf and event calendar are active on this test to make sure that it is not my custom theme or other plugins affecting it.