HooRU No, I’m not a dummy.
So you’re still using the exact versions of software from years ago? No browser version updates, no OS version updates? No changes in browser extensions or anti-malware apps?
You don’t think the speed test software has been updated in that time either? Maybe that was done while it was offline.
Multiple people have seen multiple browsers and OSs on multiple computers report funky results from speed tests on multiple ISPs that seem to go away when using the app.
Just sayin… things can change. It may not be hardware related. More testing would be recommend.