Calender and calendar sidebar - entrys missing

hello guys,
i hope someone can help me here, i bought the “vip support” but its insane how long they need to answer… and the requestions are not helpful.

specs:

  • version 9.2.2157 (5b49542)
  • one caldav calendar

problem:
in the main calender entrys are missing,but they on server and synced nad also shown in the sidebar. dont know why they are not shown in the main calendar?!