Child account unable to make any in game purchases

What it says on the tin, regardless of what I do in settings, my son is unable to make purchases from within games. Seems to be able to do so via the store, but these addons are not available outside of the games themselves. Confused as to what exactly
is blocking him. When he attempts to do so it says it's prevented by settings and advises we changes something in /family settings/manage family members, but there's literally nothing there related to purchases besides changing the passwords, which are already
working correctly.

:)