Over the last 6 months, and increasing number of websites don't open on Firefox. I've noticed it most consistently on any of the wikipedia/wikimedia pages, but it's not just those. When I type in an address and press return, or click on a link, the browser just acts as if nothing has happened. There does not show me the loading symbole. If I ask it to open a new tab with the site, the address appears on the tab, but the page itself is just black. Other browsers have no problem loading the same sites. I am on a mac, and using a VPN. Restarting the browser doesn't help, though restarting the computer sometimes does.

Thank you,