Hi Joe,
I'm seeing this problem again. Site is running 2.3.8.1 with ECP 3.4.0.4. The problem doesn't happen when you un-check or check "All Day" but it does happen when you change the start time. I've figured out that the "Ticket Note Instructions" textarea is getting focus after the start time is changed. If you follow these steps using Chrome, you'll see Chrome's annoying orange field outline show up around the textarea for the note instructions after changing the start time.
- Click add event
- Check the Requires Registration checkbox
- Uncheck the All Day checkbox
- Change the start time
If there is a way to stop that textarea from getting focus, that might solve the problem completely.