You may also want to turn on 'set time zone based on location'.
Also, on the calendar event, click 'view more' and ensure the correct time zone is there.
I should also add it's affecting all events.
I've tried to replicate the issue, and mine is working just fine. Have you tried sending in a report to SSM?
If not here's some steps to guide.
Submit an error report after replicating the issue
Samsung Members app > Get help > Send feedback > Error reports