Ok, further investigation.

Looks like it is the LAN (cable) part if the Experia Box that is the problem.

I’ve used my cell phone to connect to the Exp box via Wifi - then USB tethered the mobile to my PC - basically using my mobile as a Wifi adapter. It works! Speed is back to normal,

So, how do I fix the ethernet/lan part of my Experia Box. I’ve tried restarting it. I have the latest Experia Box (black - latest verison).

Do I need to factory reset the damn thing? (would be sorry to lose all my wifi settings etc. )

Full reset has not resolved the problem.

I can also confirm that this issue has started after the latest Boxupdate form KPN.

Hi @Shaka! Welcome back. Thanks for testing. Unfortunately, a reset did not solve the problem. As mentioned in your first post. How did you measure this 950/950? Via a wired or wireless (Wi-Fi) connection? If this was over a wired connection, the LAN port(s) could not be the cause of the speed drops. What else have you connected to the modem? think of: wifi-boosters, switches, etc. 
 

Can you test -a wired connection- with another device maybe? Just to rule out that it is your laptop (port). 

Hi @Shaka! How are you doing?  Were you able to resolve the issue yourself? 

Solved. you may close the thread. multiple resets worked.

Did it always throttle like that or was that halfway through?

I’m on my 500/500 line now - first minute of transfer I’m hitting 450mbit/s uploads which is good, but after a while it drops to 250 - 300 mbit/s….

Just upgraded to 1000/1000 to see if that same pattern happens there. If it does (950mbit for a minute and then → 500mbit), KPN is throttling my line If it remains at 250 - 300mbit it might be something else..