PS4, same issues for the past two weeks. Did my own speed tests and contacted my ISP and all is working well on my end. I get into a dungeon, however, and it's lag city. It's worse during the evenings. I can't farm an instance or run dungeons or anything. This is very disheartening, considering Heavensward is right around the corner...

ISP - Centurylink
Server - Excalibur
Location - Utah, United States of 'muriKAH