I think in your Google DNS trace your router was "de-prioritizing" the expired ICMP packets PingPlotter was sending it. It's not an uncommon thing for intermediate hops to do this. You can read more about this here.

What you should take from this is that your home network appears to be ok. The next thing to test would be your ISP's network. You can do this by starting a trace to hop 2 of the Google DNS trace (90.247.64.1). If you see issues here, you're likely dealing with an issue int heir network.