Time Keeps Changing – Time Zone Drop Down Empty

I’m quite confused as to what is happening here. I am trying to set an event for May 26th from 8:50-10:45am. Every time I do so (3 attempts now), all seems well, but after about half an hour I notice the time has changed to 3:50-5:45pm. If I go into the post to edit the time, it still shows as the original 8:50-10:45am. Manually entering the time again seems to temporarily fix it, then it goes right back to the wrong time. This seems like the only event that is doing this?

I thought possibly the event was set to the wrong time zone, but when I clicked on the timezone drop down menu it’s completely empty so if this is the case, I have no idea how I would change the time zone.

Thank you in advance for any help or insight you can provide!

The page I need help with: [log in to see the link]