Your speeds are OK. See if a firmware update is available for your router.
...you seem to be making a lot of assumptions...
My assumption was based on the idea that there was a problem with the router.
suggestions which can lead to a lot of complications and can probably break things rather than fix them
Such as having a non tech savvy User updating the firmware on a router as a 1st response. Checking for wireless conflicts doesn't risk bricking the router.
keep in mind the OP is not tech savy.
Since the OP is not tech savvy, he can't be relied on to give an accurate assessment of his symptoms.
...some of the solutions are not apt for this scenario , a Wireless interference or switching to Wired is not the right approach to troubleshoot the issue and neither is contacting the ISP or checking the physical connections.
Switching to wired connection is a safe troubleshooting step for a non tech savvy User. It rules wireless in or out as the cause, without an attempt at a firmware update, using a link from the authoritative and reliable computer troubleshooting website "WikiHow".
and neither is contacting the ISP or checking the physical connections.
Both of these are safer than updating the firmware on the router. Also I question whether or not you can rule-out the modem based on the information given by the OP.
The error faced by the OP is specific to the Browser, root certs, OS and AV filters.
One, it was two browsers, and so not "browser specific", and two how can you know this based on the information given by the OP. Also I'm not certain AV's even have filters. That sounds like techno mumbo-jumbo what one normally gets from people that don't know anything about computer troubleshooting. How can a "filter" possibly slow down an internet connection, possibly from a single site (eBay). Seems to me that if the AV were doing this as a legitimate (but misguided function) the access to the site would either be ON, or OFF. Can you post a link showing the existence of these "AV filters"? I don't believe in unicorns, either. Finally, since the OP had "bad internet" when the AV was turned on, and now has "good internet" with the AV turned off, I wonder why. Since when does AV block and/or slow-down commonly used sites like eBay? I wonder if the malware that was interfering with his internet connection is now free to do whatever it wants because the AV has been turned off. If he's a large enough scale eBay marketer, and doing financial transfers via his computer, I can easily see how someone might want to record that information (credit card numbers, etc...) Sometimes the "screen shot" function of keyloggers, and possibly malware, slow the computer down. Maybe it slows the internet connection too.
Plus explain his really weird and bad internet speed and ping numbers at first.
Also "bricking" means that the firmware update fails such that the router is permanently broken, heavy emphasis on the word "permanently", and I was not the one that made this suggestion. I simply reacted to it in as non-confrontational a manner as possible. Telling a User to update his firmware and giving a link to a "general how to" without even knowing the exact make & model of the router, instead of giving the User a link to the specific instructions for that specific router is what should have been done, and was not. I was making the best of a situation that was created elsewhere.
Bottom line: The OP didn't try to update the firmware on his router as a 1st response to a problem that seems to be caused by something to do with the AV. Or malware. I call that a "win". And now I've raised the spectre of malware. All in all, a good day, AFAIC.
