Finally I found what was wrong.
The issue lies in the wrong parsing logic from the default calendar module about repeated full-day events with TimeZone by RRULE.
If you have installed CX3 v1.8.2, Reinstall again or back to 1.8.1 (I rolled back again to 1.8.1)
Then see this;
https://github.com/MMRIZE/MMM-CalendarExt3/wiki/To-fix-wrong-repeated-fullday-event-displaying-(MM-2.27)








