Facebook Doesn't Connect on Personal Windows 10 PCs

EDIT - Windows 10, not Windows 8 (probably changes something)

At home I have three different computers, each running the same Microsoft accounts and Windows 10. Unfortunately, as of about a year ago, none of them have been able to connect to Facebook. When I try to open the site, it attempts to load for a while and then throws up an error. This happens across all the internet browsers I use - Chrome, Edge, and Firefox. The errors I get are varied: On Chrome I'll usually get ERR_TIMED_OUT, or ERR_CONNECTION_REFUSED. On Firefox I'll get Secure Connection Failed. On Edge I'll get a "Hmm, we can't reach this page."

Any ideas? Perhaps something with my system settings, or my Microsoft account?



RELEVANT DETAILS? -------------------------------------

• Facebook connects on every other computer. In fact, one of my computers is an iMac which I can reboot in Windows or back at any time, and Facebook connects perfectly in the Mac OS, just not on Windows.
• When I got a new, pretty high-end computer, right off the bat Facebook was unable to load. We had already connected it to my other two computers and added our Microsoft account by that point - maybe that might be the problem?
• Google Search and YouTube often also have this problem, but only around half the time - the other half I can access them completely and without problems.
• I've tried multiple methods of fixing the problem, only to be met with the same annoying error. Things I've tried (though I may have made a mistake; I don't want to rule it out):

- Deleting all caches
- Lowering security for Facebook
- Updating all browsers and the OS
- Disabling all add-ons and customizations

As far as I can tell it's not a browser problem, because I recently installed Firefox (importing nothing and changing no settings) and it still didn't load.