I have an issue on my computer which seems to come from NetWorx: I have a fiber optic Internet infrastructure of 100M/1G. When I download at 700 Mb/s and up I am experiencing lags on my computer (even mouse is lagging) and the connection speed is going up to 800 Mb/s and dropping down to 650 Mb/s. Without NetWorx, the bandwidth is steady around 945 Mb/s.
At lower speeds than 700 Mb/s there are no lags or other issues.
It looks like you have the "Ignore local traffic within in the LAN" option turned on.
When this option is enabled, NetWorx has to analyse every chunk of data to decide whether it is local and should be ignored, or should be recorded. This may be a problem at very high speeds like 1 Gbps since it requires analysing a large number of packets. It is not a bug per se, but rather a product limitation you have reached.
The only solution here is to turn that option off and monitor a specific network adapter instead. This method works with any speed up to 1 Gbps and beyond.