Hello. I'm still affected by a bug that is listed as fixed, while using EPiServer.CMS.UI 12.19.0. I want to use an IList<EventDateBlock> property on my page. EventDateBlock is defined as such:

[ContentType(AvailableInEditMode = false, GUID = "F6D64C68-DE4A-422B-99CD-65B92AED8C32")]
public class EventDateBlock : BlockData
{
    public virtual DateTime Date { get; set; }    
    public virtual string StartTime { get; set; }    
    public virtual string EndTime { get; set; }
}

When publishing a new version of the page, a new draft is immediately created. This only applies to the "All Properties" view, "On-Page Editing" works as expected. I believe this bug needs to be revisited.

// EDIT
It seems to only happen if either StartTime or EndTime is not set. If I make sure every property in every EventDateBlock has a value, it works as expected and no new draft is created.