I'm running the last core version of Zorin and i'm experiencing troubles with random disconnections with ethernet.
The PC is setted with a dual boot, i have no trouble at all on Windows. It's not hardware, not a cable issue, not a router issue. It's only on Zorin.
When i'm using the computer, the ethernet connection is lost for 10 to 120 seconds randomly, multiples times per hour. It's really annoying when being in online meetings or uploading huge files.
Whatever if i unplug/replug the cable, i just have to wait for 10 to 120 seconds and the connection restore.
It's random, and really annoying. All external causes have been eliminated.
Help appreciated, it's ruining my work lately... And ha, i formatted PC last week for a fresh new Zorin install to try solve this, but unfortunately... The formatting didn't helped.
I recently had this issue and to me it's a problem with the cable pins, they might be weak after many years of use. In fact when I plug them to charge my phone a small movement to the cable stops the charge. If you move the cable a bit close to where it's plugged to the device and it disconnects briefly then the cable should be replaced or fixed.
One thing I ran into a long time ago, although I would've thought this type of issue wouldn't be a thing anymore, is that sometimes running Auto MTU size (usually 1500) used to be the cause of a pain, and depending on the router, you would need to change it to match because the communication between the two couldn't figure it out sometimes. For example, my current router I have is currently set to a default MTU size of 1478? Something like that. I wouldn't think this would be an issue anymore, but I suppose if you're out of ideas you could check your router and see if there's something special setup.
My last idea (at least for now) is disabling the firewall temporarily, then use the ethernet ONLY IN SERVICES YOU TRUST AND CONSIDER SAFE, don't visit weird or sus websites or when your computer will be hacked or broken I'd feel guilty for suggesting so . When I first tried ethernet with my simple pocket modem it just worked without any additional action from me, just plugged and turned it on, done . Yours might be a professional router , in that case I have no experience.
. When I first tried ethernet with my simple pocket modem it just worked without any additional action from me, just plugged and turned it on, done 
. Yours might be a professional router 
, in that case I have no experience.