Changed to 3G only and streaming works, for 15 minutes, then the router shuts down completely. Have to switch it of and on again manually and then it works for another 10-15 minutes before it goes black again..... Shall I return the router?

@Mallevs 

I have this exact same issue. I also live in Sweden and use Tele2. I have version 1 of the MR400 though.

My PC works fine, but not the other devices I have, for example, PS4, Nvidia Shield, Galaxy S9, Philips Hue and more. My brother came for a visit with his Iphone X and that worked. An old Android phone I had lying around also works. But not the mentioned devices. Things like Youtube, Netflix, Gmail, Reddit, Google, and lots of other stuff doesn't work if I'm on my connection.

If I use my phone as mobile hotspot everything connected to my phone works. But if I use my PC (that has no issues) as hotspot, nothing connected to that works. My phone SIM doesn't work in my router either (same carrier), but my SIM works in my neighbor's router, so there's nothing wrong with the SIM's that I've tried.

I contacted support and got a link to the beta firmware for MR400 v3: https://static.tp-link.com/2019/201912/20191217/LTE_GATEWAYv3_1.11.0_0.9.1_up_boot(191216)_Add_MTU_Setting.zip

I was asked to change MTU value to 1300. Can be found under Advanced > Network > Internet

Unfortunately, since I have version 1, I was unable to update my router.

As other have mentioned, forcing 3G only makes all my devices work again, but I get dropped connection almost every minute, so it's very unstable. Then again, the router reports only 25% signal strength on 3G. If I switch back to 4G Only or 4G Preferred, all the devices stop working again.

@nu1mlock 

I have the same issue, also on Tele2/Com Hem. It is only the Samsung Galaxy Tab SM-T580 which is not connecting properly to the router. All other devices are and the Tab is also connecting to the iPhone when I am sharing wifi. Also Tele2 on the mobile phone. 

How do I update the firmware? 

I have v3 on the router. 

@nu1mlock 

I have v3 and don't have that option. 

"I was asked to change MTU value to 1300. Can be found under Advanced > Network > Internet

Unfortunately, since I have version 1, I was unable to update my router."

To update your router firmware follow these steps:

1. Download this file: https://static.tp-link.com/2019/201912/20191217/LTE_GATEWAYv3_1.11.0_0.9.1_up_boot(191216)_Add_MTU_Setting.zip

2. Unpack the file

3. Login to your router

4. Click the Advanced tab

5. Click System Tools on the left menu

6. Click Firmware Upgrade on the left

7. Click "Browse" and pick the update file

8. Click "Upgrade" and wait for it to reboot

When it's done, go to the Advanced tab again, press Network > Internet in the left menu. Change the MTU value to 1300 and save. This option should be available after the update.

I don't know if this fixes the issue as I haven't been able to try since I have version 1.

TP-Link support didn't seem sure if it would work, but they asked me to give it a go. Hopefully it works for you. Please report back when you've tried it! If it works for you it might work for others and TP-Link might be able to add the fix for version 1 as well.

@nu1mlock 

It seems to work! Restarted the tablet, I have changed programs on Netflix a couple of times, and the quality of the image looks ok. 

Although still just 25% signal strength, when I tried 3G I had 75% but then it crashed (before installing the firmware). 

@nu1mlock 

I had 25% before aswell...so no improvement there. I am just happy the tablet stopped buffering. 

Hope it works out for you too. 

I'll keep you posted if anything changes. Is anyone at TP-Link monetoring this thread? 

@Kevin_Z 

Do you have any information regarding a beta firmware for v1 with the MTU setting? It seems that the beta firmware worked for at least one user, but the only firmware available is for v3.

@Mallevs Hello, after firmware update (HW V3) I can change to 4G in settings but I still get 3G speeds? For me it looks like the settings does nothing now.

I can connect all devices as on 3G and I have not had any problems with disconnted devices (Streaming and TV works).

So still 3G speed even with the test firmware :(

Best regads

Joakim