Hi wdunwoody, I got some "hickity" results earlier today with a default profile - Standard ETP and no extensions - but, that seems to have smoothed over now.

Try disabling your Avast extension, restart Firefox and test again.

It is possible that (anti-virus) security software is causing the problem. Try to disable security software temporarily to see if that makes a difference.

Thank you for your reply... I have indeed disabled antivirus protection, but no change. The DSL Reports Speed Test offers the option to disable HTTPS for the test. This also has no effect...

Have you tried a speed test at another site, like your ISP?

A few other suggestions: Reboot your router/modem Check your cable connections Check that the firmware in your router/modem is up-to-date

Also,

Malwarebytes AdwCleaner https://www.malwarebytes.com/adwcleaner/

has Basic Repair Actions on the Settings tab which can quickly reset your internet connectivity settings.

I have indeed rebooted the router, with no change. I have to verify the ethernet connections, computer to router and router to Verizon ONT. The Verizon speed test... will absolutely not even START. Ookla and one other show... normal 95+ mb/s down and up when DSLR test shows 95+ down... and zero to 11mb/s up. That's what is so weird! I've run Malwarebytes... nothing. Avast scan shows nothing. Haven't done McAfee Stinger yet... that has helped odd problems in the past.