@gazza35 

** UPDATE **

I've been playing around with the settings and changed it to 4G Only and all of a sudden it picked up the network and started working fine (albeit with a very weak signal) 

Then changed back to 5G Preferred and straight away it failed again, so it looks like the issue is to do with 5G and possibly signal strength.

Strange as when I was trying it in the office earlier there's a good signal strength there as I'm on the same provider with my phone and I had a full and strong 5G signal on the premises

  @Joseph-TP 

Hi Joseph

Many thanks for the response

Yes, it does seem to be just the 5G that is causing issues.  I can get it working pretty much every time with 4G now but absolutely nothing at all on 5G.

To answer your questions:

1.  I didn't try this specific SIM card in a mobile phone but in another older TP-Link router (4G only) which explains why it was working fine now that we know the problem is 5G related.  I do have an EE 5G SIM in my mobile phone and can confirm that is working fine with a good 5G signal from the exact same location where I tried 5G with the Deco originally.

2.  I have taken screenshots from both 4G Only and 5G Preferred so you can see the difference.  Please note that this is not from the original location that I first tried the Deco, I have brought it home to test further and the signal strength is pretty poor here for some reason.  The end result is exactly the same though, working fine on 4G but as soon as I switch to 5G I get the red light and it's reporting no signal.

4G Only:

5G Preferred:

Many thanks

  @Joseph-TP 

Hi Joseph,

An update from further testing this morning.

I've brought the router into my other office location which is in the city centre and there's a much stronger signal here.  Started in 4G again and all was well.  Decided to do a speedtest with Ookla and got a very respectable 140mbps down which was impressive.

I then switched to 5G Preferred and exactly the same happened again, ie loss of signal and the red light.  I powered the Deco off and back on and it came back to a red light.  I got distracted by something else so left it like that for a while.  When I came back the light was solid white which I'd not seen before.  When I looked at the manual that said it was a 5G signal!  So much to my surprise I went into the app and yes, it's reporting as 5G with good signal strength so was very happy with that. However when I've done a speedtest again with Ookla on 5G I'm only getting between 8mpbs and 11mpbs down versus 140mbps on 4G so something still not right unfortunately.

I'll send screenshots now with the 5G connected:

  @Joseph-TP 

Further update, I've just changed server on the Ookla speedtest and am getting 288mbps down now so much better.

Could the issue simply be signal strength?  Stil intrigued why it locks up in other locations with the red light though.  Will try again later in the other suburban office where this is going to be the main source of internet.  

** Even further update! **

I've just retested the server I got 288mpbs with and I'm only getting around 15mpbs now.

The original and more local server I initially tested and only got 11mpbs with, I'm now getting 438mpbs!  

Seems to be a wild swing in download speeds, not sure why that would be.

  @gazza35 Hey there, im having the exact same issue with the same router and EE sim. Could you please show a screnshot of what your APN is? with the EE card on the router so i could test it on mine and thanks. And any news about your speeds now?

having the same issues with the X50 5g

First deco wouldnt connect to my EE sim, spent hours trying to sort it out, but supplier ended up collecting the Deco. they had no issue with it when they inspected it and returned it to me.

It worked for 4 months, although dropped out a few times for an hour or so.

Speeds of 250mbps in daytime and 390 in middle of the night.

switched on one morning and got the red light. After many attempts at rebooting, light stayed on red!

Did a factory reset and cleared apps cache and data and guess what... still a red light

Contacted supplier, who sent a new sim card to me, same again, red light.

Tried the new sim in an older TL mr6400 4g router and it worked fine at 4g speeds.

Used Deco as a wifi router and it worked well.

Contacted supplier again, who arranged for TP Link to senf out a new ( replacement) Deco , same model.

Cleared cache and data from app, dleted and did a fresh install of app.

Set up network on Deco, and same as before, get the red light before it completes creating network.

Definately something to do with the way the X50 5g works with EE's 5g network is the problem.

5g phone on EE works fine sat next to the Deco, so its not signal related.

Have arranged to return this Deco to the supplier, whose also baffled why it doesnt work and I'm having a differant TP 5g router instead.

The app is hit and miss as well, took 8 attempts at deleting the previous X50, saying 'it can't be done, try refreshing the page'

Bitterly dissapointed with it and wished I'd never bothered buying this model.

If it wasnt for the Vodafone 4g in  my area going downhill ( .5 mbps at 10pm) I'd of stayed with my pold mr6400 albeit at 4g speeds.