

I’ve seen warnings like that when a sites certs expire. Well maintained sites don’t usually let that happen, but I’ve seen it plenty for torrent sites. It’s usually fixed in a few hours or a day.
Like others said, it could also be the ISP, so you can try a VPN, even a free one would probably do, if that was the issue.
You can also try resetting cached data for that site specifically. How to do that is different per browser, search online for more info specific to your browser.

Seems aight, I’m fine with FF ATM though.
I do keep alternates around for rare issues, so when helium is out of beta if it ever is, I may install it.