How is the powerline adapter connected to Archer D50?Is it connect to the LAN port of D50? If so,it should be a compatibility issue between and the PLC.It can't recognize this PLC. Maybe you can try...

Maybe you can check the system log and check what is causing this.

If the bandwidth is enabled,the data will go through CPU. CPU will control the bandwidth to each client and will do a lot of calculate. So it will cause decrease of the bandwidth. If not...

Is Sumsung S7 downloading files when you connect it? If it's downloading files,other devices will have very low Internet speed. And some software will download in backround,maybe you didn't notice it.

After reset the router and reconfigure it,is the wireless network works normally? I think it will solve the problem. If the problem remains,I recommend you use the previous firmware.

You are a good boy:rolleyes: