In my app I'm using internal testing (5 testers) and open testing.

This month I had 15 days of Ad serving is currently limited due to invalid traffic concerns.

Now they enabled ads again without any apparently reason but the advise is still there.
I have over 3.5 millions of app openings per month and for sure I don't show and click my real ads during the development phase.
My doubt is that is not possible to show ads in the internal testing publication or the prelaunch/firebase tests.
AdMob team does not reply to my question and I don't know how to avoid this issues in the future.
How can I do?