Hello,

When the router lost the connection, can you still able to login the router's management page and do you still have WAN IP address there? 

Please put the SIM card into your phone and test the internet stability, if you can get a stable connection, put the SIM card back to the router. And login to the router's management page with the manual below. 

https://www.tp-link.com/en/faq-783.html

Then go to Advanced>>Wireless>>Basic Settings, change the channel to 1 or 6 or 11, channel width to 20Mhz( if you are using 2.4G wifi), change channel to 36, channel width to 40Mhz( if you are using 5G wifi), save the settings and test the  internet stability again.

If the issue still exist, check the firmware vesion and make sure it is up to date.

Hi,

Yes, I can access router but it only says smthng no connection, reboot -> works fine.

I don't believe this kind of problems are referred to channel options, because connection is cut off from every device which is connected to this router.

Sim card works fine and has been working fine in Huawei router for few years, so it's not pending of it. And the firmware version is up to date, checked that also.

Searching through internet many users of this router has reported same kind of issues and general opionion is that this device heats up and it causes router to freeze and only way to proceed using it is reboot.

Imho, it's unaccebtale for this kind of device to have this kind of "feature".

Hello, thanks for your reply.

Meanwhile, what is the internet/WAN IP address when the M7350 stopped working?

Besides, please go to system-system log to save it and export it to us.

Thanks in advance, and have a nice day.