PS4 suddenly very poor internet connection

Got a new talk talk router the other day and it works fine for all my devices. However my ps4 is a different story, it has very poor connection to the router. I am using the Ethernet cable but a download that should take me about 10 hours (I have very poor internet any ways) is now taking around 35 hours and because all my other devices are fine it must be my ps4.
Please can I have some help, thank you very much.