TestCafe fails to load page styles / CSS

All my TestCafe tests suddenly started running strange, TestCafe is able to run the test and open the URL but pages load without the CSS, they are somehow blocked by the TestCafe proxy or my company proxy or something. I have tried all browsers without any luck. OPening the page manually using the same proxy works!

I'm running the tests behind a proxy and ignoring certificate errors like

testcafe chrome   ./src/tests/test.js --env=dit --ignore-certificate-errors --proxy-bypass XXXXXX

This is how they look in the browser:

I have TestCafe version 1.10.1 and Node 6.12.0. Chrome 87.0.42. These tests were working fine and suddenly started behaving like this.

This was also reported here: https://github.com/DevExpress/testcafe-hammerhead/issues/1920