Imported Apointments are automatically Changed to UTC!

Can anyone help with this error? When importing appointments from an Outlook application via .isc file, all imported appointments are set to (UTC) Coordinated Universal Time. After correcting the time zone on (UTC+1) Berlin, the original time changes by minus 2 h and the following error occurs: [Exchange Web Services] EndDate before StartDate. After “Edit element” the start time is 13:10 and the end time 13:50; both with the same date and time zone Berlin?