I have the same issue with Avast Pro.
At start it seemed like Avast is blocking the CSS file for Netflix but then I started noticing that Avast was blocking some sites entirely like the microsoft homepage and avast homepage.
Only way to use the web now is to turn off Avast entirely.
Thank you for reporting this issue.
Could you please help us gather some logs for analysis?
First enable debug logging: GUI → Settings → General → Maintenance → Enable debug logging
Then reproduce the issue (Have Real Site turned on and try to visit some of the pages that you have issues with.).
Then create support package and submit it (https://www.avast.com/en-us/faq.php?article=AVKB33) and post the ID of the created package here so we can find it.