In 4.8 Preview 4, I was able to repro the issue where the pins disappeared when split. However, this is fixed in our latest internal build because the nodes themselves have been completely overhauled. You should see them working properly in a future update, likely 4.9.
As for the missing pins, this has also been fixed with the new time nodes.
As a workaround, can you use the Timespan and DateTime functions directly?
