I clicked on all the new things and they are not being shown as new anymore but as soon as I change to a different category and back, the highlights are also back.
Probably a corruption of the file ReticulatedSplinesView.
- Delete the following file: Documents\Electronic Arts\TheSims 4\ReticulatedSplinesView.
- Start the game to recreate the file
- By deleting the file, all new highlights will be set back and you need to click on everything again. This time it should stick though.
- If you don’t want to click on every object/clothing, you can also use this method to remove all the highlights in one go: Manually removing New Highlights