Try downloading Firefox from Mozilla. Download, unzip, and run firefox-bin from the folder and see if you have the same issue. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

It loads fast for me from NJ. Here is the add-on I'm using to show load time. see screenshot https://addons.mozilla.org/en-US/firefox/addon/load-time/

Who are you using for DNS?

Operating System: openSUSE Leap 15.6 KDE Plasma Version: 5.27.11 KDE Frameworks Version: 5.115.0 Qt Version: 5.15.12 Kernel Version: 6.4.0-150600.21-default (64-bit) Graphics Platform: X11 Processors: 16 × AMD Ryzen 7 PRO 6850HS with Radeon Graphics Memory: 62.1 GiB of RAM Graphics Processor: AMD Radeon Graphics Manufacturer: HP Product Name: HP EliteBook 865 16 inch G9 Notebook PC

Thanks for the suggestions. After wrestling with the problem for another hour this evening, I have a solution: disable one of this machine's two network adapters. I have no idea why it works, but it does. Using either one of them is fine; using both causes slowdowns and failures, but only with Amazon. I have no idea why.

There's no need to read on unless you're interested, but here's the message I wrote while debugging the problem. I'll paste it here in case someone else gets these symptoms and wants to try what worked for me.

---

The results of sideloading Firefox surprised me, and I can't make sense of them. Firefox 126.0 from Fedora still has the original problem. Fedora 127.0, downloaded from Mozilla, worked partially at first — it would load the bulk of an Amazon page, but there'd be missing elements. (Most obviously, when I hovered over the image gallery on a product page, images wouldn't load.) After a couple of retries, Firefox 127.0 wouldn't load Amazon's home page at all. Chrome has now started showing the same problem as well. But Firefox 127.0 in a VM running Fedora 40 still runs sweetly. All other pages work well in all browsers outside the VM, too. So there's some problem that's common to all browsers outside the VM, but which doesn't affect browsers inside the VM.

Ping times to amazon.co.uk are high, both inside and outside the VM, but not outrageous:

$ ping -nc6 amazon.co.uk | tail -1 rtt min/avg/max/mdev = 28.056/91.496/152.326/44.569 ms $

I've just tried disabling IPv6 in Linux, and it made no difference.

For DNS, I'm using <https://quad9.net/>, filtered by a Pi-Hole. Disabling the Pi-Hole makes no difference. Neither Quad9 nor the Pi-Hole has a performance problem:

$ time nslookup amazon.co.uk 9.9.9.9 | grep 'Address: [1-9]' Address: 178.236.7.220 Address: 54.239.34.171 Address: 54.239.33.58

real 0m0.070s user 0m0.009s sys 0m0.013s $ time nslookup amazon.co.uk 192.168.0.10 | grep 'Address: [1-9]' Address: 54.239.33.58 Address: 54.239.34.171 Address: 178.236.7.220

real 0m0.054s user 0m0.007s sys 0m0.013s $

Changing Firefox's "DNS over HTTPS" setting from "Default protection" to "Off", so that I always use the Pi-Hole, makes no difference.

I tried a couple of other things on the newly downloaded Firefox 127.0. Clearing the startup cache returned me to the original condition, where pages at least start to load, even if they then got stuck. Refreshing Firefox (and immediately reloading the Load Time extension) had the same effect.

Actually, pages do often load, but they can take several minutes to do so. For one page, the Load Time extension says:

Loaded 2024-06-13 19:52:17.388 Load Time 252.01 s Redirect 8.16 s Domain Lookup 0 ms Connect 0 ms Wait for Response 3.41 s Response 0 ms DOM Processing 240.35 s Parse 56.42 s Execute Scripts after Parsing 1 ms DOMContentLoaded Event 72 ms Wait for Sub Resources 183.85 s Load Event 84 ms