"Error" message related to 2 PS4 on one PSN main user

[Vidings]

I have tried to set up 2 PS4s at home for my kids. Have tried to set up the two PS4s so they can play with one PSN user, meaning so we are able to play a purchased game from my main user from both PS4s. I have used the guiding I have found online on how to make the 2 PS4s linked to the same main PSN user (one main/old PS4 user that originally was linked to the PSN accoount and a new user linked to the same PSN accoult). Their main interest now is to play Fortnite together, but we are only able to start PS4 from the main/old user. When trying to start Fortnite from the new user I get an error message that seems to be related to age (see attached picture). I have been in the parental control and opened up for age restrictions, and cannot find where else an age restriction possibly is. Could anyone assist in how we can fix this issue. Thanks for your help!!