@bezoss Wanted to answer this since it's the weekend for David. According to this article V3.20 isn't the same firmware as V4.20 so you shouldn't try to install it.

@gnz Please see my response here

@gnz Going to tag one of the members of the tp-link staff on this but it seems it only affects a few archer routers and non deco WiFi extenders. As I am ubale to post the list i sent you a link to it...

@Nahemoth Won't lie I'm not sure what the best filters would be so going to tag a member of the tp-link staff who might know. @David-TP

@Nahemoth Shielded Ethernet cable provides superior protection against electromagnetic interference (EMI) and noise but is more expensive, thicker, less flexible, and requires proper grounding,...

@David-TP