The issue sounds similar to what @Jov posted a while back here: Node downtime after adding second node
I am still suspecting it’s an indication that the router can’t keep up. Try restarting it first, see if that helps. If not try resetting the router settings. I had a similar issue in the beginning where connections were dropped intermittently. Resetting my router fixed it. I believe based on the other topic you have an Asus router as well, so it might be a similar issue. While you’re at it, make sure it has the latest updates. Also check the router logs for errors.