@Kevin_Z  I am also experiencing the same problem. It can happen several times in an hour. Actually the same provider (different SIM) is used in my phone and the connection is stable. My first intention is to replace my phone with TL-MR100 as wireless router to save my phone battery. But the problem with the disconnection is quite disturbing.

Please find below some information about the problem:

1. Ensure you are running the latest firmware TL-MR100(EU)_V1_201016 first.

<-- Verified, it is the latest firmware

2. When you all mention the connection is not stable, are both the wired connection and wireless connection dropping when connected to the MR100? Can you still see the wireless signal from the MR100 on the wireless devices? Try to modify the wireless settings, such as wireless channel to 1/6/11, channel width to 20MHz, then reboot the router and reconnect to the network to confirm.

<-- There is no problem with the wireless (WiFi) signal, my devices are still connected to the TL-MR100. During the problem, I also login to the TL-MR100 to troubleshoot the problem. I notice during the problem, the "Internet Status" keep showing "Detecting..."

3. Who is the SIM card carrier? Are you able to get a stable internet if you put the SIM card on a phone?

<-- Indosat Ooredoo (Indonesia). As mentioned above I get a stable connection with my phone using the same provider (different SIM)

4. Please confirm if the band is changed to a different one when it loses the connection, you may compare that when the internet is working fine and when you lose the connection. Try to manually select one.

<-- I have manually selected band 3, even then I see a quick drop in connection. The Router "Intenet Status" show as "Detecting..." in the management console during the drop.

Just happened a couple of minute ago. Twice within 15 minutes.

@Kevin_Z Thanks for your reply. I have set the DNS server according to your suggestion. Does the TL-MR100 periodically check the connection to the DNS server? So you are thinking maybe there is nothing wrong with the LTE connection but there is a problem with connection to the DNS server? I wll get back to you after trying the new setting for a while.

I bought it about 5 weeks ago. If I am not mistaken, the problem has been happening since the beginning. Initially the TL-MR100 came with older firmware. Because of the problem, about 3 weeks ago I upgraded to the latest version to fix the LTE band. 

@Kevin_Z It just happened again after I set the DNS server. During the problem, I also can't ping 8.8.8.8. Please find attached the log.

@Kevin_Z Thank you. I hope your engineer may be able to solve the issue. The problem is quite disturbing because it can happen within a very short periode.

@Kevin_Z 

Hi here,

Same issue here.

Tried all solutions found here, still get disconnected from LTE WAN and Wifi every 30second.

Also noticed I got some weird ICMP behaviour when trying to ping MR100 from linux laptop over wifi:

64 bytes from 192.168.0.1: icmp_seq=12437 ttl=64 time=1.84 ms
64 bytes from 192.168.0.1: icmp_seq=12438 ttl=64 time=5.16 ms
64 bytes from 192.168.0.1: icmp_seq=12439 ttl=64 time=7.14 ms
64 bytes from 192.168.0.1: icmp_seq=12440 ttl=64 time=3.55 ms
64 bytes from 192.168.0.1: icmp_seq=12440 ttl=64 time=4.05 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12440 ttl=64 time=7.28 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12440 ttl=64 time=21.5 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12441 ttl=64 time=67.2 ms
64 bytes from 192.168.0.1: icmp_seq=12441 ttl=64 time=105 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12442 ttl=64 time=5.23 ms
64 bytes from 192.168.0.1: icmp_seq=12443 ttl=64 time=64.5 ms
64 bytes from 192.168.0.1: icmp_seq=12444 ttl=64 time=184 ms
64 bytes from 192.168.0.1: icmp_seq=12445 ttl=64 time=20.5 ms
64 bytes from 192.168.0.1: icmp_seq=12446 ttl=64 time=1.86 ms
64 bytes from 192.168.0.1: icmp_seq=12447 ttl=64 time=52.1 ms
64 bytes from 192.168.0.1: icmp_seq=12447 ttl=64 time=64.5 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12447 ttl=64 time=86.5 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12447 ttl=64 time=92.8 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12448 ttl=64 time=73.7 ms
64 bytes from 192.168.0.1: icmp_seq=12448 ttl=64 time=76.8 ms (DUP!)
64 bytes from 192.168.0.1: icmp_seq=12449 ttl=64 time=26.6 ms

...

Please note there's only these 2 devices (laptop and TL-MR100) on network (no switch, other AP or hosts) so DUP may not being caused by loop path.

I do confirm same SIM does works correctly in my mobile phone, and same laptop behaves normaly with same test when associated to mobile sharing 4G data)

Also noticed that these "dup", "latency" and 4G/Wireless disconnections is more frequent/visible when trafic increases.

Hope it help