Glad to help. This works with every game. You can (force) a add-on to download again.
Follow the steps and it's no problem.

Follow my guide. Do not go to PlayStation store the regular way

No need for PS4 user to uninstall the game. You can download the DLC again. Do not start the game. 1) go to "Library" in PS4 start menu 2) go down to "Purchased" 3) chose Farming simulator 17, then the game page starts. Here can you see all the trophies, overview, trending ... An...