Hey, guys

I'm new to OpenWrt, so I would really appreciate your help with my problem.
I installed the latest stable build on my TP-Link Archer C7 v2.0. Everything went smoothly, I configured the device according to my needs and thought that was it.

I made my home server available online with port forwarding and this is where I got stuck. On the first glance the server works - ssh connection, web-server, mail-server, everything seems fine. But when I connect to the server from outside (Internet), I only stay connected for about a couple of minutes: ssh disconnects with 'Broken pipe' message even if it's not idle, and when I try to upload some big file to the web server, the connection drops after some time as well.

I checked the network-related kernel settings (with sysctl -a) and even compared them to those of dd-wrt router (which worked perfectly in the same setup), but still couldn't find the reason why the connections stop.

So, now I'm stuck and would really appreciate your help! I don't want to return to my old router, but for now this is the only option.

Thank you in advance!