152.4 continuous loading

The most frequent culprits are: addons (the more "privacy" things you throw in sites' way, the more challenged you'd get on their delivery platforms), and mostly on Windows also 3rdparty security software eavesdropping on your secure connections, effectively stalling them. That's why there's always the recommendations to: # Compare with Private Window so that you don't bring over your old cookies and historic browsing data for the sites affected in case it's their own sessions that affect them now. # Restart into Troubleshoot Mode from Help menu to see behavior without some of the customizations and addons that can trigger many big site operators' protections. # Look into disabling your antivirus or its "safe web" features as a test. They might just be behind a bit and not have their internal rules compatible with the newest updates yet, to again be able to poke their nose into your browsing, and fail the connections now. Generally it depends on whether you see it on particular sites (and are e.g. hitting CDN delays from a common cloud provider), or it's any and every site, incl. Mozilla sites, or your local radio station or volunteer firefighters too, that most likely won't use the same kind of infrastructure. There are a bunch of connection features that you can try disabling if your security software can't handle these, it just means losing some modern optimizations, but may provide more stable transport — I can list a few if you're so inclined. If you end up downgrading, please do report the results perhaps to your antivirus vendor, so they're aware if that's the compatibility issue you're seeing.