A 35-50kB HTML document on many Stack Exchange website pages including Stack Overflow is taking 10+ seconds to load. Please see screenshots for evidence. Please note that the issue is intermittent. Same page could load fast or slow on repeated attempts to load it.
The last screenshot is of a Wiki Page. Its document size is 10x times higher than what Stack websites are loading but its loading time is very fast.
I'm on a 40Mbps fiber plan. My laptop is connected to my router via Wifi. I am not using a Proxy or a VPN. I usually get full speed if I try to download or stream something. I have no latency issues on myriads of other websites I visit on a daily basis including media rich websites such as YouTube.
DNS resolution does not seem to be an issue either. Doing a ping on Meta SE shows latency below 5ms in general, and using drill command on Meta SE returned DNS records within 3ms-100ms. Using traceroute with TCP packets shows that my machine can reach Meta SE, SO and cdn.sstatic.net within 11ms easily.
Stack Exchange websites are loading slow on both of my fully updated browsers: Firefox Developer Edition (110.0b9) and Chromium (110.0.5481.77) running on a fully updated Arch Linux OS. And yes, I did restart my machine and my router too. The problem persists.
I have tested the problem on Guest Mode of Chromium as well as on a new profile on Firefox to rule out ad-blocking and extension related issues. In general, loading time was slower most of the time in Firefox as compared to Chromium where some pages loaded fast as usual and then suddenly slow loading issue would popup there too.
And I have this problem on my Firefox for Android too by the way.
I have been facing this problem for about 4-5 days. I thought it would resolve if others might be having this issue because some of them would report it on Meta SE. Apparently other users seem to not have this problem. Suggestions on SU for this kind of problem did not help either.
So, how do I make SE websites load fast, or at least as fast as they used to load a couple of days ago?
Edit 1:
Tried on a 4G network. Same problem.
Traceroute was below 60ms. Ping was below 65ms in general. Here are a couple of screenshots.
Because 4G is slower than my broadband that wiki page also shows higher latency. But even than that fat wiki page loads alright, but SE sites don't.
Edit 2:
Links to redacted HAR files when the issue occurred. One was tested on a 4G network (hotspot) and the other on broadband (wifi). See 4G HAR and Broadband HAR.