Turn off ipv6 in the nic settings. You don't really know if you are using a ipv4 IP to get to places or IPv6. It makes troubleshooting hard. IPv6 many times has worse ping times, not sure why all the ISP have claimed ipv6 is the future for the last 20 years but they do not seem to make it a priority.
It should make no difference when you plug and unplug the ethernet. Ethernet problems generally are packet loss not packet delays. The cable itself transmits data at some fixed percentage of the speed of light. If you see packet loss in pings to your router that could be a bad cable. Anything else in the ping to the router is either the pc or the router holding the data in buffers for some reason.
Your tracert sucks, not that you can do anything about it. The ISP is hiding the response times from the most important hops 2 & 3. Maybe a ipv4 trace is different.
In any case you want to leave a constant ping run in the background to your router ip and to hop 2 or whatever the first hop that will respond. If you see issues to hop 2 it represent the cable coming to your house. Be very sure you are not exceeding the bandwidth you purchase either up or down that will cause delays in connection to your house.
I have turned off ipv6 and run a PingPlotter test for 10 minutes to my desktop, router, the 2nd hop and google.co.uk
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Note: the flat lines maybe caused by the fact that I had an interval of 2.5 seconds
PingPlotter test for desktop:
https://prnt.sc/t8242r
General question, why would I have latency above say 1ms to ping packets to the device im using? Especially that one ~7ms spike in the graph.
PingPlotter test to my router/DEFAULT GATEWAY IP, this was done earlier than the ping to my desktop:
https://prnt.sc/t81mye
I have noticed there are 2 big spikes, one to 2.8ms and one to 7ms. What could be causing those?
PingPlotter test to my 2nd hop :
https://prnt.sc/t81ln8
I guess the 2nd hop does not let me ping it? On the website, for a graph like this it says it could be like this because "One of the routers between the computer running PingPlotter and the destination is not passing through ICMP echo requests or not allowing ICMP TTL expired packets to return."
I had rerun this test about an hour later and I am still getting this graph and the 100% PL stat.
PingPlotter to google.co.uk:
I ran this test for about 15 minutes, set the interval to 1 second, to be able to see everything I had to increase the timescale to 30 minutes, notice how the latency scale is at 2350 ms. There is also a jitter graph, what is jitter?
Note: 2nd hop has the same IP as the 2nd hop I pinged earlier.
https://prnt.sc/t81zwy