New Internet Switch over from BT to EE highly unstable

[CuddlyLuna]

Since switching over to EE to 1.6gb package my internet is highly unstable, it's impossible to play games. 
Restarted Hub multiple times
Replaced cables
Tried different devices
Reset the fibre box
Checked all cables 

It is driving me insane

[JimM11]

@CuddlyLuna What was involved for all off the steps for the switch over from BT FF to EE 1.6Gb/s change!

[bobpullen]

What do you mean by 'unstable' - what are the exact symptoms? Do the LED indicators on the hub/ONT do anything during the periods of time when you've a problem?

What game? What devices? How are they connected? Are you using the extender? How is that connected? Anything else about your network setup that is 'non-default'?

Difficult to offer help without knowing a little more about your setup/symptoms.

[CuddlyLuna]

Hi there, an engineer came in and switched the fibre box on the wall then left and that was it.

[CuddlyLuna]

The lights are fine, we are talking about micros stutters and packet lose/huge ping spikes constantly.

The in house LAN setup is fine, its the internet connection. 0 issues until the switch happened.
Everything on LAN works fine, home NAS systems work fine, tethering off my phone is fine, but the incoming connection is bad.

[JimM11]

@CuddlyLuna If you only had the ONT replaced then you are no doubt taking care off everything else on your network, report it to EE CS and have them investigate what is going on with the 1.6Gb/s speed package and the ONT upgrade to port speed!