The link rate between powerline unit are too slow.
Are there any other powerline devices in this network?
Try to plug them in a same power socket to test the link rate to make sure it's normal.
Besides, make sure they are far away from high power appliances.

I have problem with the wifi going a bit slow, what could I do to improve?

flying snow wrote

The link rate between powerline unit are too slow.
Are there any other powerline devices in this network?
Try to plug them in a same power socket to test the link rate to make sure it's normal.
Besides, make sure they are far away from high power appliances.

My desktop is upstairs. So I dont think that would be possible, how would that work?

is there any laptop to help you? Accroding to your words first, you also tried Devolo branded pair with same issue.
Firstly, we need to figure out whether your home electricity environment is not suitable to use powerline device.
If it's the electricity environment issue, it's not recommended to use powerline devices.

I dont have a laptop, any other suggestions? Because WIFI alone would never cut it in my house

Ok, so basically I tried with the Devolo 1200 Powerlines, I was getting 400mbps. So probably an issue with my wiring. I was told the TP-Link Utility only shows what your wiring is capible of, not what the adaptors are pushing out, that makes no sense to me.

So the only thing I could try is with a laptop directly from the adaptor, and I dont have a laptop. The Devolo adaptor is WIFI, I dont think that makes any difference.

I use a Sky Hub, and Sky Q, they claim to have powerline technology built in, but they are not yet supporting it, has been the cause since nearly 2 years now since release, I have tried it and it slows down the wifi.

I dont know what to do, some of these answers helped whilst some didnt. Possibly could be interference from mobile chargers etc, but really I cant win. where else would we plug them?

Probably would have been a better solution to have some switches or access points installed, I have spent nearly £300 on these adaptors and cant take them back, nobody wants to buy them either.

So would be helpful if someone with a bit more knowledge could help me out, I dont think the adaptors are at fault considering the speed pushed out from the Devolo, or my wiring situation.

Could it be faulty cables? Can I win? As I have leads coming out of all ends easy to pull on some of them. Anybody can help me. Thanks

The adapters may very well be at fault ... given the ever-revolving firmware issues and lack of updates and fixes here at TP-Link, I do not trust them for any kind of sustained traffic anymore, let alone for realtime IPTV streaming. Just go with the devolos.

I don't play wih adapters or books

400 Mbit physical line bandwidth across floors sounds pretty normal to me. What kind of problem did you have with the devolos?

Either way, the #1 leap in powerline performance and reliability is to put a devolo 1200 DINrail into the main fusebox, and feed it LAN from the router. This is particularly true if you're trying to feed an entire house, not just a single flat.

What do you mean by fuse box? We have a wall socket for one phone line. Also are you saying I should ditch the TP’s and go back to the Devolo’s? Bear in mind I can’t take the TP’s back because the shop no longer exists.Currently the TP’s are first connected downstairs with a Ethernet cable going into one of the 2 yellow sockets, the second upstairs one cable into my desktop and the other a Ethernet hub. Sounds about right doesn’t it? I am by far not smart with certain technologies it’s more about time. Also could the 5ghz of my router be affecting the adapters? Is there anything else like settings on my router dchp, unpnp etc? Just trying to find a possible conflict or issue here