The Happy at Home event items now keep showing up as new in the build/buy catalogue. This is also true if you switch categories. Thankfully, the items only have stars. While it isn't a game breaking ...
Ideas
Status changed:
New
to Troubleshooting
They are working fine for me so could try moving Documents > Electronic Arts > The Sims 4 > ReticulatedSplinesView to the desktop. This will make most items show as new again but check if they now stick if you mark them as read again.