I just realized that this works as expected in a private browser session, or after creating a new profile, which led me to the assumption that this is probably extension related.

1. I removing all extensions from my default profile, which didn't help. 2. I tried installing ublock origin to the newly created profile and I could identify that this indeed breaks things (same with adblock plus)

However, the issue remains even after removing the extension. Meaning, I can only manage to restore correct behavior by either using private browser or creating a new profile. As soon as I install an adblock extension once, this breaks.

Restarting the profile using about:profiles and 'Restart with Add-ons Disabled' also has no effect. The issue remains.

Note that Troubleshoot Mode does not fully disable extensions, any modified prefs are still retained.

uBlock Origin changes the following about:config settings:

network.dns.disablePrefetch = true
network.http.speculative-parallel-limit = 0
network.predictor.enabled = false
network.prefetch-next = false

Hi,

Thanks for your reply. Unfortunately resetting these options doesn't help. I even tried to reset all modified settings in about:config without any luck.