Is there maybe a simple way to test and compare (quantify) the network performance between Jarvis and Krypton?
Some SSH command to measure up/down Mbit/s?
You could do a wget, but that would test the connection speed of LibreElec and not so much Kodi which is what you would like to quantify in this case. Plus; there are add-ons for that that are far easier to use than SSH. iPerf is another option I suppose:
iPerf - The TCP, UDP and SCTP network bandwidth measurement tool
But I wonder what you would get from it. I doubt it has anything to do with LAN/WAN throughput and more to do with the coding in Kodi itself