Anyone else been driven up the wall by these issues? Over the last two or three weeks I've noticed two major ones in particular:
1. When the 'Https Everywhere' extension is applied, it is difficult, and usually impossible, to get embedded YouTube videos to appear on WP.
2. More seriously, if one tries to disable or remove 'Https Everywhere' from one's browser, Cloudflare seems to block all attempts to get back into WP.
The following may be a solution:
Uninstall the browser, including all settings, browsing history etc, then reinstall from scratch.
Install the extension 'Smart Https' (which is a development of 'Https Everywhere', it seems).
This extension allows you to switch from Https mode to Http by clicking on a green or a red icon in its control panel, without leaving the page you are on.

Here's the 'What are you listening to THIS VERY SECOND' page with the HTTPS option enabled (green icon):

And here's the same page with the Http option (red icon):

A huge advantage of using this arrangement is that Cloudflare doesn't seem to notice or care which setting you are on. For me, it allowed WP to load in either https or http mode, without even doing the '5 second' browser check.
It might be possible to do this without reinstalling the browser, but maybe it's better to ditch all accumulated junk..
_________________
On a mountain range
I'm Doctor Strange