I am using Event Collision plugin together with Recurring events plugin, when I try to move event over other event, the dragged event is incorectly converted to full day event (this state is not saved to DB) and after refreshing page event is where it was befere moving it.
To replicate this bug just include Event collision plugin to samples/03_extensions/15_collision.html and try it (sample doesnt have scheduler.config.multi_day = true;scheduler.config.full_day = true; config options, so the event just disapers and is not displayed)