I am developing an android game, which I would now like to test with my children (it's an online game, so playing it with my family seems like an obvious option at this point). So I've uploaded it on Google Play Console, and set up an internal test. My wife was able to install it using the link I sent her, but when my children (9 years old) tried, they got an error message stating the the app was blocked by parental control and could therefore not be downloaded.
The only parental control software I use, is Google Family Link. I've temporarily tried to allow all apps (regardless of age limit), but that didn't work. Is internal testing simply not available for children, or is there some setting I've overlooked?