@Kevin_Z 

Hi Kevin

1. The lights show the same as if the connection is still working

2. All connected devices regardless of connection type suffer the same issue total loss of internet connection. No this only happens in the router.

3. I have got the full text log file if you need it

4. Firmware is up to date version posted to this thread. I do not have another SIM card to try

@MR400-84 

I am having the exact same problems with the exact same symtoms.  I constantly run Speedtests on my home network since I switched to a Three SIM for data instead of expensive fibre internet.

I have also fitted an external aerial to my house and get a very good signal from this now - download speeds increased by at least 20MBPS compared to the fibre connection.

So when it works, it is good.

But lately as you, it drops out and I have to reboot the MR400 router, but this is required now pretty much every day.  I have even set the MR400 to reboot every day at 06:00 in the settings.  

Very frustrating.

I will try another SIM - from my mobile phone (also Three) to see if it is the SIM perhaps.

@Benadie911 I have also tried the same things as you. I have been emailing TP link for weeks now and their only suggestion is the router must be faulty. The issue I have is they want me to pay to send them the faulty one they will then dispatch the next working day a new one. So if you can approach where you purchased it you might have more luck. I got mine from eBuyer and their solution is much the same except they will collect from me for free but it would mean being without for max 30 days. Neither options are suitable for me.

@Kevin_Z no still battling to get it sorted. Struggling to get a reply now. They want me to send the faulty unit back before they dispatch the replacement. 

@MR400-84 @Kevin_Z . it seems a bit confusing as I can not quite establish if the problem of the internet dropping off is to all the devices connected (a range of laptops, a desktop PC, tablets, phones, TV, XBOX) or if it is only certain devices that suffer this disconnect.

The last week or so it would seem that devices like phones and tablets tend to drop off and say that their WiFi connection does not have internet access. I then run over to the MR400 router to check the lights and the Internet light is still on and I have at least 2 or 3 bars signal. I check on the PC and or the TV and they can still access the internet and when I run a speedtest, I get expected results (30-40 down and 15 to 30 up).

The webserver always shows 75% or 100% signal with good wireless signals.

As I write these are:

SIM Card Status: SIM card prepared.

Signal Strength: 100%

RSRP: -80dBm

RSRQ: -7dB

SNR: 21.8dB

I have now changed the auto restart to 13:00 from 06:00 as it seemed that restarting early in the morning did not last the whole day.  Not sure if this made a difference...time will tell.

I have also manually updated the router to the V3 firmware that is listed for the IBM security update from the one on the router at time of purchase (which the "check for update" said did not need updating).

Now: Firmware Version:1.12.0 0.9.1 v0001.0 Build 190730 RC.59984n 

@Fintan.. 

I tried various settings as well. I even got an experimental firmware sent to me by tech support and sent them lots of diagnostic data. None worked. I eventually gave up and got a refund form Amazon and bought a Huawei B535 router. That was nearly 10 months ago and have had no problems with it.  It is a Cat6 router as well, so much faster than the MR400.

Hope this helps.