It’s more than likely a simple router cache issue, try this before all the other trouble shooting, too easy:
# Turn off your PS4™ and unplug it from the power source.
# Unplug your router or modem from the power source. Sometimes connecting issues are caused by internet router WIFI signals, unplugging it will help troubleshoot the connection issue. Locate the small reset button on the back of the DUALSHOCK®, located near the L2 button.
# Use a small, unfolded paper clip or something similar to push the button inside the tiny hole. Hold the button down for roughly 3-5 seconds and release.
# Then, re-connect your DUALSHOCK®4 (micro USB port located on the back) to your PS4™ (USB port located on the front), using the USB cable that came with your PS4™.
# Plug your PS4™ into a power source. *'''''Don't plug your internet router in at this time'''''.* Press the PS button on DUALSHOCK®4 controller and then log into your profile. If you don’t already have a user profile created, find the instructions at: “Creating and Deleting User Profiles” on PS4 (type that in at Sony website support page search)
# Plug your router back in - done!