I forgot to mention everything is connected via wifi, any idea if a 10m ethernet cable hardwired to ps4 would resolve it?
YES, assuming you have a decent connection speed.
We watch Netflix here all the time and I have absolutely no issues with latency / pings when playing on my PS4 while other people are watching Netflix, in fact I have had Netflix running on my PC while playing on the PS4 and still no issues.
My guesses are that everything is using Wi-Fi at your place, if so that might / will cause issues like you are seeing.
I say try and wire in Ethernet cables where you can and get yourself a 1Gbit Network Switch to plug all the cables in (assuming the ports on the router isn't enough), doing so you will see a huge improvement.
We only use Wi-Fi here for Tablets and Phones, everything else is wired.
Edited by PaulKirby (Tue 30-Jul-19 07:29:53)