Ibis Paint X conflicting with age restriction

Having trouble with the age settings where Ibis paint X is a 13+ app, when the settings from parent controls are 4,9,12&17+ respectively

When the settings are placed to 17+ there are no issues using this app, however when I bring it to 12+ unsurprisingly this locks the app by not meeting age requirements. I do not wish for my child to have access to the 17+ category however they need this specific app for school. Can you please provide suggestions?