The most popular fix to this is to set up new connection and when prompted choose manual when prompted, leave everything else Auto except DNS, using Google's public DNS 8.8.8.8 & 8.8.4.4 respectfully, for the download, should open the flood gates.

It unfortunately doesn't work for fixing the patch error people had but it takes my download speed on FFXIV from 3.5mb/s to 10.5mb/s, a roughly 40 minute start to finish download on PS4 vs 2+ hours.