Here are the links:
Latest Update: https://www.playstation.com/en-us/support/system-updates/ps4/#update-internet
If you want to reinstall from scratch, the following link will describe how to do that and provide a download:
I would only do this if the update doesn't seem to work.
If the solution above fixes your problem, please don't forget to rate my service (Excellent, Good and OK will allow me to be compensated for assisting you). If it doesn't, please let me know and I will continue working with you until we resolve the problem.
I would be happy to call you, but please be aware that this is an additional service which requires an additional fee. I will send you an offer for this additional assistance. Just accept it if you would like the phone assistance.
This is Gary from JustAnswer. Just checking in to find out if you were able to update your PS4. Please let me know how it went and if you need additional assistance.