@David-TP 

As I stated in my original post my internet service provider uses an MTU of 1420. This is why I want to change it. When I use the deco mesh system I get really high pings. When I only use the ISPs modems wifi I do not get high pings. They told me I need to change the MTU to 1420 to mitigate this if I choose to use my own router. 
 

I feel failed by TP Link. I used to love this brand. It's sad to see features being stripped away altogether and others now requiring a subscription for something that should just be part of a 300.00 + router. 
 

When is this firmware update coming because I've already ordered a Dynalink mesh system and plan on returning this Deco system.