They do staged rollouts, maybe a-b testing. It seems to generally be region based rather than platform.

You might need to check that you are using all appropriate blocklists as well. The subreddit usually has a sticky/pinned post for YouTube related issues as this has been a slow moving target for about a year now.

Do you have other extensions? For example, I can see that uMatrix is also blocking all requests to doubleclick.net

I'm on Windows 10.

Ubuntu.