Nextcloud Calendar shows Deck Completion Times Incorrectly

I am running the latest Nextcloud version 28.05.5. It is directly installed onto my fileserver running on the latest Ubuntu Server OS. In other words, it is not installed using Snap or Docker. Recently I installed Nextcloud Deck so I can track my to do list.

In the Deck app I configure a task to be completed on May 12th at 8:00AM and save it as a task. And here is the problem.

When I look at the same DECK task on my Nextcloud Calendar app in a browser from within my Win10 client PC I see that my May 12th Calendar square shows my DECK task with a 4:00AM completion time and not 8:00AM. I also installed the DECK app on my Android phone and the DECK app on my phone shows a 4:00AM completion time and not 8:00AM.

I have already clicked on my Calendar’s gear cog for my Nextcloud instance running on my Ubuntu fileserver and I have confirmed my time zone is set to “America/New_York”. So that can be ruled out.

What could possibly be causing my Nextcloud Calendar app to show my DECK card tasks with completion times that are 4 hours too early? And why does the DECK app installed on my Android Phone show a 4:00AM completion time on my phone but the DECK app up running on my Nextcloud fileserver shows the 8:00AM task completion time I programmed.

Any advice welcome.