My own appointments are viewed as external appointments in the app after being entered in Outlook on my laptop and then synchronized on my smartphone. Although I don't invite anyone to the appointments and only use them as reminders for myself. I can then falsely confirm or reject them. If I do this, the app returns problems. When I enter the same appointments directly in the app it works perfectly normal. I recently added a new calendar to one of my synronized accounts and since then I am experiencing this problem.

I am using version 5.6.0 (400201) on a Samsung