theverge.com (among other sites) hang/delay before rendering in Brave

[Brave-Matt]

Description

I’m wondering if anyone can tell me what causes some sites to have a short “delay” before rendering (and rendering correctly).
For example, theverge.com and overclockers.co.uk both have this behavior (off the top of my head, i believe there are more I’ve encountered) but do load as intended. These sites load much faster in Chrome. In Brave you generally get ~1-3 second delay:

@snyderp notes the logic at play:

<style>.async-hide { opacity: 0 !important} </style>
<script>(function(a,s,y,n,c,h,i,d,e){s.className+=' '+y;h.start=1*new Date;
h.end=i=function(){s.className=s.className.replace(RegExp(' ?'+y),'')};
(a[n]=a[n]||[]).hide=h;setTimeout(function(){i();h.end=null},c);h.timeout=c;
})(window,document.documentElement,'async-hide','dataLayer',4000,
{'GTM-54FC4VZ':true});</script>

Further, it seems that the script says "Delay render for 4000ms (4s) unless "google optimize" is detected.

Steps to Reproduce

1. Visit theverge.com or overclockers.co.uk (for example)
2. Note the page delay on load before rendering

Reproduces how often:

Always

Version/Channel Information:

This issue occurs in all channels Release - Nightly

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
  No, but it seems as though the delay may be slightly shortened although it's hard to tell. Regardless, rendering time is still comparatively slow to Chrome and Chrome + uBO which render the site instantly.

Miscellaneous Information:

User report: https://community.brave.com/t/slow-rendering-https-www-overclockers-co-uk/59075/4

[bbondy]

weird, thanks for the report!

[LaurenWags]

Verified passed with

Brave	0.66.98 Chromium: 75.0.3770.100 (Official Build) beta(64-bit)
Revision	cd0b15c8b6a4e70c44e27f35c37a4029bad3e3b0-refs/branch-heads/3770@{#1033}
OS	Mac OS X

Verification passed on

Brave	0.66.98 Chromium: 75.0.3770.100 (Official Build) beta(64-bit)
Revision	cd0b15c8b6a4e70c44e27f35c37a4029bad3e3b0-refs/branch-heads/3770@{#1033}
OS	Linux

• Verified page load was instantaneous

Verification passed on

Brave	0.66.98 Chromium: 75.0.3770.100 (Official Build) beta(64-bit)
Revision	cd0b15c8b6a4e70c44e27f35c37a4029bad3e3b0-refs/branch-heads/3770@{#1033}
OS	Windows 10 OS Version 1803 (Build 17134.523)

• Verified page load was instantaneous