Have you tried scanning your computer recently for viruses/malware? Is there any unusual network related software there that makes lots of connections (sorry I already hinted at this)?
Here is GlassWire Elite in Click to block mode running on my PC right now as I have Chrome/Firefox both open with multiple tabs.
I'm using an older small NUC that isn't very powerful.
Is your GlassWire closed when it shows this CPU usage, or is it open and viewable? You can click its top right X to close it out and it will still run in the background.
Of course if GlassWire is running and in use (making a graph and not minimized) it will use a reasonable amount of CPU just like any other Windows application that's open and being used.