Hi,
our Mica users have problems entering a start/end date for data collection events. I couldn't figure out why and I noticed the same problem in your demo version, so I guess there could be a bug.
Describtion:
When you enter a start date of a data collection event, Mica indicates that the field does not validate. Eventually the warning message disappears, but there is a banner at the top of the page saying "please fix the errors below", even if every field is marked green now. You are unable to save the page at this stage.