edit: a single web search reveals that Flutter has indeed Google telemetry enabled by default. developing your web searching skills is a good habit for developers.
I already know this, just flutter config --disable-analytics
solve this problem.
But there are more than this. For example, Flutter itself doesn’t work correctly. It needs the Android SDK (that is installed separately). And with this you need to accept the licenses and other stuff. That’s the point.
compile the most basic of flutter apps or some demo and see if the app makes any kind of request to the internet.
How can I intercept this traffic quickly?
In my experience. I didn’t like Murena. I used it for a while (I think 6 months. I don’t remember well). And yes, it’s “ok”, but the interface is a bit broken.
The good thing is that there is a lot of software you can use there: OnlyOffice, NextCloud (much of their software), Searx and even Gitlab are there.