In Memotoo I have two events with yearly interval, but at the first thuesday of
the month instead of a fixed day. In Evolution these events are non repeatable
events after sync. I downloaded my data from Memotoo, opened the calendar file
and searched the event. The rule are:
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=1TH

If I change this in Evolution, after sync the repeats are lost at Memotoo.

The same is with frequency monthly and interval 12. It seems there is some
misunderstanding between Memotoo, Syncevolution and Evolution. And in Evolution
I can only choose monthly if I have not a fixed day.