Browser running in docker fails to load (some) JavaScript from webpage

So the problem is this:
When opening some websites (e.g. https://iamstripes.com – most of the urls load correctly, this is a example that doesn’t) in a docker image, the webpage is not rendered correctly and clearly there is some JavaScript missing from the page.

If the same website is opened in local browser, then everything is loaded correctly.

I’ve tried multiple docker images, from selenium based, "simple" docker images only with browser and even sause labs instances and all of them with the same result.

My first assumption is that I’m missing some sort of flag when starting the browser, but I’ve tried (almost) everything suggested in the interwebs without success 🙁

TL;DR
Browser (chrome, firefox) launched in docker fails to open the URL correctly
Browser (chrome, firefox) launched locally opens the URL correctly

example docker image:

docker run -d --name=firefox -p 5800:5800 -v /docker/appdata/firefox:/config:rw jlesage/firefox

and then you can open the docker browser using http://localhost:5800 in any browser window

Several browser options I tried when launching the browser in a docker selenium (missing some here):

--disable-security
--no-sandbox

Also in Chrome capabilities:
excludeSwitches: ["enable-automation"]

I’ve tried with and without these settings, and in the case of Firefox even went directly into the browser about:config and changed some security parameters there directly as well, without success.