vlad.grb

At some point of time whole wired network becomes unavailable. The dashboard says that 0 devices connected when 3 of them are connected using 1Gb cables. Reboot though admin panel not working. Only if I disconnect them then power off then power on the router and plug cables back it works fine for few weeks and then repeats again. It started a 1,5 months ago. The Wifi works fine when wired connection is down. How can I figure out the issue? Where I can get more knowledge regarding this type of issue?